Changes in free amino acid profile in goats with pregnancy toxemia

Pregnancy toxemia is a metabolic disorder that afflicts goats when the heightened energy requirements preceding parturition are not sufficiently satisfied. At present, the potential association between pregnancy toxemia and the free amino acid composition in hair goats remains uncharted territory. The purpose of this study is to investigate the free amino acid profile in goats during the pivotal three weeks preceding delivery, distinguishing among those with subclinical pregnancy toxemia (SPT), clinical pregnancy toxemia (CPT), and those in the control group (CG). Additionally, the study aims to investigate any potential relationship between the amino acid profile and beta hydroxy butyric acid (BHBA) levels. The researchers analyzed a total of 50 goats, comprising 20 goats with SPT, 20 with CPT, and 10 in the CG. The serum free amino acid profile was determined using a gas chromatography flame ionization detector (GC-FID) device. BHBA concentration in goats with CPT and SPT was significantly higher than KG (p < 0.001). Furthermore, in goats with CPT, the glucose concentration was significantly lower than in CG (p < 0.012). In goats with CPT and SPT, the concentration of valine, one of the gluconeogenic amino acids, was significantly higher than in control group (p < 0.001), while histidine concentration was significantly lower (p < 0.020) than in control group. Specifically in goats with CPT, the concentrations of alanine (p < 0.002), serine (p < 0.001), and threonine (p < 0.043) were significantly lower than in control group. Moreover, the concentration of phenylalanine, which is both a glycogenic and ketogenic amino acid, was significantly lower (p < 0.028) in goats with SPT compared to the control group. The Fisher ratio (p < 0.010) and Glycine/Alanine ratio (p < 0.001) were significantly higher in pregnancy toxemia goats with than in control group goats, indicating a poor nutritional and energy status of the goats during the prepartum period. In summation, the findings of this study underscore that amino acids exhibiting marked concentration variations hold considerable promise in the diagnosis, prognosis, and therapeutic management of pregnancy toxemia.

Use of Hydrogen-Rich water in rice milk preparation improves the nutritional and sensory properties of product

The effect of using hydrogen-rich water (HRW) in the preparation of rice milk on the nutritional and sensorial properties was evaluated. The physicochemical parameters (pH, Eh7, titratable acidity), sensory properties (color), and minerals (ICP-MS), as well as amino acid (UPLC-ESI-MS/MS), sugar (HPLC-RID), and aroma (SPME-GC/MS) profiles, of four varieties of rice and their milk and waste were examined using Principal Component Analysis (PCA). Results showed that the profile of minerals, sugars, amino acids, and aroma was affected by the use of HRW. HRW-treated milk showed an increase in some essential minerals (Na, Mg, K, Ca, and Se) in some rice varieties. While HRW application enhanced the levels of desirable aroma compounds in milk but not the undesirable ones. This use of HRW allowed to increase in some essential amino acids (Ile, Leu, and Met) in HRW-treated rice milk samples.

An improved method for determining free amino acids by RP-HPLC/DAD with o-phthalaldehyde derivatization: Method evaluation in beers and wines

Rapid methods for amino acid determination are desired to reduce running times, and the main factors involved in the rapid separation of these compounds in HPLC are the columns, solvents, and gradient. The present study refers to a method optimization to rapidly analyze 19 amino acids in RP-HPLC/DAD with pre-column derivatization using o-phthalaldehyde. To evaluate the method's robustness, Indian Pale Ale-IPA beers and wines from the San Francisco Valley-SFV and Chapada Diamantina-CHD, Brazil, were analyzed. The method showed acceptable linearity (R2 > 0.992), precision (CV < 3.96%), recovery (74.2-113%), detection limits (<0.56 mg/L), and quantification limits (<3.62 mg/L) and separation gradient in 18.5 min. IPA beers were discriminated from wines by arginine, asparagine, tryptophan, alanine, phenylalanine, and tyrosine contents. Furthermore, CHD wines were discriminated from SFV wines by asparagine, glutamine, arginine, cystine, tyrosine, and leucine. In conclusion, a rapid method for amino acid determination was optimized and validated for wines and beers.

In vitro DIAAS of Swiss soybean cultivars using the INFOGEST model: Increase in protein quality from soybean to soymilk and tofu

To support the transition towards more sustainable and healthy diets, viable alternatives to foods of animal origin need to be identified. Many plant-based protein sources are currently marketed with claims of minimal environmental impact, but very limited consideration has been given to their protein quality and bioavailable mineral content considering the fact that animal-based foods are typically the primary source of both in Western diets. In this study, traditionally consumed soy foods (cooked soybeans, soymilk, tofu) from different Swiss soybean cultivars were nutritionally characterized and the in vitro digestibility of individual amino acids and total protein were assessed using an in vitro model based on the static INFOGEST protocol; the protein quality was evaluated using the in vitro digestible indispensable amino acid score (DIAAS). The results reveal an increase in total protein in vitro digestibility across the traditional soy food production value chain: 52.1-62.7% for cooked soybeans, 84.1-90.6% for soymilk, and 94.9-98.4% for tofu. Protein quality, determined using the recommended amino acid pattern for 0.5-3 years old, was "low" (no claim) for cooked soybeans (DIAAS < 60), while soymilk (DIAAS = 78-88) and tofu products (DIAAS = 79-91) were of similar "good" protein quality, with considerably higher DIAAS values than those of cooked soybeans (P < 0.001). The iron and zinc contents in soy foods were substantial, but high molar ratios of phytic acid (PA) to iron (PA/Fe; >8) and PA to zinc (PA/Zn; >15) indicate a possible strong inhibition of iron and zinc bioavailability. Based on the DIAAS results, soymilk and tofu would be suitable plant-based alternatives to animal-based foods, while future efforts should focus on optimizing soybean preparation to overcome the negative effects of the plant tissue matrix as well as processing steps to reduce mineral absorption inhibiting substances.

Fava bean (Vicia faba L.) protein concentrate added to beef burgers improves the bioaccessibility of some free essential amino acids after in vitro oral and gastrointestinal digestion

The influence of partial replacement of animal protein by plant-based ingredients on the protein digestibility of beef burgers was investigated. Beef burgers were supplemented with fava bean protein concentrate (FB) or a mixture of FB and flaxseed flour (FBFS), both processed by extrusion, at different levels: 0 (control), 10, 15, and 20 % (w/w). A pilot sensory analysis was conducted to select the percentage of flour inclusion for further assays: control, 10 % FB, and 10 % FBFS. Protein digestibility, amino acid profile, and protein secondary structure of these burgers after in vitro oral and gastrointestinal digestion were studied. In vitro boluses were prepared with the AM2 masticator, simulating normal mastication, and static in vitro digestion of boluses was performed according to the INFOGEST method. Inclusion of 10 % FB in beef burgers did not alter their flavour or tenderness compared to the control, whereas tenderness and juiciness scored slightly higher for the 10 % FBFS burgers compared to 15 % and 20 % FBFS ones. Poor lipid oxidative stability during storage was observed with 10 % FBFS burgers. Total protein content was significantly higher (p < 0.05) in 10 % FB burgers than in control burgers after in vitro oral digestion. Additionally, 10 % FB burgers presented higher amounts of free essential amino acids like isoleucine, leucine, phenylalanine, and valine at the end of digestion, as well as methionine, tyrosine, and histidine. Partial substitution of meat protein by 10 % FB improves the nutritional profile of beef burgers, without altering their sensory qualities.

The nutritional composition and cell size of microbial biomass for food applications are defined by the growth conditions

BACKGROUND

It is increasingly recognized that conventional food production systems are not able to meet the globally increasing protein needs, resulting in overexploitation and depletion of resources, and environmental degradation. In this context, microbial biomass has emerged as a promising sustainable protein alternative. Nevertheless, often no consideration is given on the fact that the cultivation conditions affect the composition of microbial cells, and hence their quality and nutritional value. Apart from the properties and nutritional quality of the produced microbial food (ingredient), this can also impact its sustainability. To qualitatively assess these aspects, here, we investigated the link between substrate availability, growth rate, cell composition and size of Cupriavidus necator and Komagataella phaffii.

RESULTS

Biomass with decreased nucleic acid and increased protein content was produced at low growth rates. Conversely, high rates resulted in larger cells, which could enable more efficient biomass harvesting. The proteome allocation varied across the different growth rates, with more ribosomal proteins at higher rates, which could potentially affect the techno-functional properties of the biomass. Considering the distinct amino acid profiles established for the different cellular components, variations in their abundance impacts the product quality leading to higher cysteine and phenylalanine content at low growth rates. Therefore, we hint that costly external amino acid supplementations that are often required to meet the nutritional needs could be avoided by carefully applying conditions that enable targeted growth rates.

CONCLUSION

In summary, we demonstrate tradeoffs between nutritional quality and production rate, and we discuss the microbial biomass properties that vary according to the growth conditions.

A novel approach for the protein determination in food-relevant microalgae

Microalgae are gaining interest as food ingredient. Assessments of functional and nutritional properties are necessary to forward their implementation. In this study, protein content and composition of eight commercially available microalgae biomasses were determined and compared to conventional food proteins. A novel procedure for the determination of the true protein content was proposed: Multiplication of proteinic nitrogen with a sample-specific nitrogen-to-protein conversion factor kA. The proteinic nitrogen was derived from the difference of total nitrogen minus non-protein nitrogen. The average kA for microalgae was 5.3 and considerable variation between different microalgae biomasses were detected. In addition, the content of non-protein nitrogen varied between 3.4% and 15.4%. The amino acid profiles of Chlorella samples were nutritionally superior to the tested plant proteins but indicated lower protein interaction tendency, potentially limiting their structuring functionality. In contrast, Auxenochlorella contained lower amounts of indispensable amino acids while showing comparable interaction potential to plant proteins.

Nutritional quality and physicochemical properties of biscuit from composite flour of wheat, African yam bean and tigernut

This study investigated the effect of the supplementation of wheat flour with flour blends of African yam bean (AYB) and tigernut for the production of biscuits and evaluated the sensory characteristics. The composite flours were of ratio 70:25:5 (TWB), 70:20:10 (ATW), 70:15:15 (BTT) for wheat: AYB: tigernut, respectively, while 100 % wheat flour served as control (WTY). The composite flour samples were analyzed for proximate, functional and pasting properties. The physical and chemical properties and sensory attributes of the developed biscuits were carried out. The moisture, protein, fat, ash, crude fiber, carbohydrate, and energy contents of the composite flour ranged from 6.63 to 8.13 %, 11.22-18.36 %, 13.27-19.15 %, 0.98-0.99 %, 3.96-7.43 %, 59.97-62.55 % and 400.89 to 410.40 Kcal/100g, respectively. The results showed that protein fat, ash and crude fiber of the biscuit were improved. The water and oil absorption capacity of composite flour was low while the pasting properties of the composite flour blends reduced as the AYB flour increased. All the composite flour blend biscuit samples possessed high essential nutrients and antioxidant potential. All the biscuits samples were accepted by the panelists, however, sample BTT (70 % wheat flour+15 % AYB flour+ 15 % tigernut flour) was most accepted in appearance, aroma, taste, crispness and overall acceptability. Therefore, biscuits from the flour blends of wheat, AYB and tigernut could be nutritionally beneficial and good for adults.

Fortification of Chlorella vulgaris with citrus peel amino acid for improvement biomass and protein quality

The amino acid extract (protein hydrolysate) from various citrus peels was employed as an organic nutrition source for the culture of Chlorella to investigate their effects on the biomass and protein quality of the microalgae. The major amino acids in citrus peels included proline, asparagine, aspartate, alanine, serine, and arginine. The most plentiful amino acids in the Chlorella were alanine, glutamic acid, aspartic acid, glycine, serine, threonine, leucine, proline, lysine, and arginine. Adding the citrus peel amino acid extracts to the Chlorella medium enhanced overall microalgal biomass (more than two folds p < 0.05) and protein content (more than 1.25 fold, p < 0.05). Citrus peel amino acids increase essential amino acids and decrease the non-protein amino acid of Chlorella (p > 0.05). The present research shows that citrus peels have good nutritional quality and could be used for the inexpensive cultivation of Chlorella biomass with potential utility for food application.

Elucidation and quantification health-promoting phenolic compounds, antioxidant properties and sugar levels of ultrasound assisted extraction, aroma compositions and amino acids profiles of macroalgae, Laurencia papillosa

Currently, sustainability is one of the most critical issues confronting society today. The growing of macroalgae in ocean farms appears more sustainable than agriculture on land due to it does not require any fresh water, chemical fertiliser, or soil. Macroalgae have been shown to be a sustainable marine source of amino acids, novel bioactive phenolic and aroma compounds that can be exploitation in food, cosmetic, nutraceuticals, pharmacological applications. Despite starting the huge cultivation of macroalgae in world, bioactive compounds in the edible macroalgae have not been well characterized. Ultrasound assisted extraction (UAE) and conventional extraction (CE) techniques were compared and red macroalgae, L. papillosa extracts were characterized. The highest amount of amino acid was glutamic acid (GLU) and composed of 35% was essential amino acids. UAE at 10% amplitude for 15 min showed significantly highest (p < 0.05) phenolic (212.03±3.03 mg gallic acid equivalent/100 g) as well as antioxidant activity determined by DPPH (105.69±3.02 µmol Trolox/100 g), ABTS (238.69±2.23 µmol Trolox/100 g) radical assay and FRAP value (72.47±3.13 µmol Trolox/100 g) when in comparison with CE. Furthermore, bioactive compounds in extracts were indicated as phlorotannins, flavonoids, phenolic acids and other polyphenols using liquid chromatography coupled to diode array detection and electrospray ionisation tandem mass spectrometry (LC-DAD-ESI-MS/MS). This result confirmed higher antioxidant capacity detected with the UAE. A total of 46 volatile organic compounds were identified and quantified by GC-FID/MS with HS-SPME system. This study emerges as first report to novel extraction method used and deeply characterization of L papillosa. The results seem that significant potential application in the functional food, active packaging and nutraceuticals industry.

Effects of faba bean, blue lupin and rapeseed meal supplementation on amino acid metabolism of dairy cows fed grass silage-based diets

Information about the amino acid (AA) supply of locally produced protein supplements to dairy cow metabolism is needed to design sustainable diets for milk production. In this dairy cow experiment, grass silage and cereal-based diets supplemented with isonitrogenous amounts of rapeseed meal (RSM), faba beans (FB) and blue lupin seeds (BL) were compared with a control diet (CON) without protein supplementation. The diets were arranged as a 4 × 4 Latin Square using periods of 21 days, and four rumen-cannulated Nordic Red dairy cows were used in the experiment. The intake of all AAs increased in response to protein supplementation and was for many individual AAs higher when RSM rather than the grain legumes FB and BL were fed. The total AA flow at the omasal canal was 3 026, 3 371, 3 373 and 3 045 g/day for cows fed CON, RSM, FB and BL, respectively, but only RSM resulted in higher milk protein output. This may be explained by the higher provision of essential AA for milk protein synthesis when RSM was fed. The cows fed FB showed some positive features such as a tendency for greater omasal flow of branched-chain AA compared with BL. Overall, low plasma methionine and/or glucose concentrations in all treatments suggest that their supply was possibly limiting further production responses under the dietary conditions of the current study. It seems that the benefits of grain legume supplementation are limited when high-quality grass silage and cereal-based diets are used as the basal diet, but higher responses in amino acid supply and subsequent production responses can be expected when RSM is used.

Solid-state fermentation improves the quality of chrysanthemum waste as an alternative feed ingredient

Chrysanthemum waste (CW) is an agricultural and industrial by-product produced during chrysanthemum harvesting, drying, preservation, and deep processing. Although it is nutritious, most CW is discarded, wasting resources and contributing to serious environmental problems. This work explored a solid-state fermentation (SSF) strategy to improve CW quality for use as an alternative feed ingredient. Orthogonal experiment showed that the optimal conditions for fermented chrysanthemum waste (FCW) were: CW to cornmeal mass ratio of 9:1, Pediococcus cellaris + Candida tropicalis + Bacillus amyloliquefaciens proportions of 2:2:1, inoculation amount of 6%, and fermentation time of 10 d. Compared with the control group, FCW significantly increased the contents of crude protein, ether extract, crude fiber, acid detergent fiber, neutral detergent fiber, ash, calcium, phosphorus, and total flavonoids (p < 0.01), and significantly decreased pH and saponin content (p < 0.01). SSF improved the free and hydrolyzed amino acid profiles of FCW, increased the content of flavor amino acids, and improved the amino acid composition of FCW protein. Overall, SSF improved CW nutritional quality. FCW shows potential use as a feed ingredient, and SSF helps reduce the waste of chrysanthemum processing.

Antioxidant potential and amino acid profile of ultrafiltration derived peptide fractions of spent hen meat protein hydrolysate

Spent hen meat is considered as a category of waste generated by the poultry sector which can lead to serious environmental concerns if not disposed and utilized properly. In this work, spent hen meat was hydrolysed by 2% Flavourzyme (6.5 pH, 55 °C) followed by ultrafiltration to produce three peptide fractions with molecular weights > 10 kDa, 5-10 kDa and < 5 kDa. These fractions were evaluated for antioxidant potential, SDS PAGE and amino acid profile. The SDS PAGE profile demonstrated bands in the low molecular weight (< 10 kDa) region. Peptide fractions of < 5 kDa exhibited highest antioxidant activity and, essential as well as hydrophobic amino acid composition than whole hydrolysate and other peptide fractions. Incorporation of the identified hydrolysate fraction in food could improve its shelf stability while serving as a preventive component against human degenerative diseases.

Optimizing heterotrophic production of Chlorella sorokiniana SU-9 proteins potentially used as a sustainable protein substitute in aquafeed

Alternative protein sources for the reduction/replacement of fish meal in aqua-feeds are in urgent demand. Microalgae are considered sustainable protein sources for aquaculture due to their high-quality proteins with a complete profile of essential amino acids. This study examined the heterotrophic production of proteins from Chlorella sorokiniana SU-9. Culture parameters for maximal biomass and protein production are as follows: glucose - 10 g/L glucose, sodium nitrate - 1.5 g/L, and iron - 46 μM iron in BG-11 medium. Under optimal conditions, biomass content, protein content and protein productivity of SU-9 reached 4.14 ± 0.20 g/L, 403 ± 33 mg/g and 382 ± 36 mg/L/d, respectively. The protein profile of Chlorella sorokiniana SU-9 is comparable to fishmeal and soybean meal. The essential amino acids arginine, lysine and cysteine, along with glutamine and glutamate, were high. The production cost of SU-9 can be significantly reduced under heterotrophic cultivation conditions, making it a potential protein substitute in aquafeed.

Effect of Moringa oleifera seed flour on the rheological, physico-sensory, protein digestibility and fatty acid profile of cookies

In the present study, debittered Moringa Oleifera seed flour (DDMF) rich in protein, vitamins, minerals and balanced amino acid and fatty acid profile was used to develop functional cookies. DDMF was incorporated at 25, 50, 75 and 100% levels and studied their effect on flour rheological, physicochemical, micro-structural, sensory and nutritional properties of cookies. The results revealed that the addition of an increasing amount of DDMF from 0 to 100% increased water absorption (59.5-77%) by farinograph study; cookie dough hardness (89.2-284.7 N); decreased pasting temperature (60.2-30.1 °C) and peak viscosity (696-9 BU) by amylograph study. SEM studies of cookies indicated that, in control cookies, starch granules are completely gelatinized and enmeshed in the gluten protein matrix, whereas, in 50% DDMF incorporated cookies, partially gelatinized starch granules are seen embedded in a weak protein matrix. Sensory evaluation showed that incorporating DDMF, up to 50% of cookies had clean mouthfeel without any residue formation and were highly acceptable; however, beyond that limit, they became brittle. The addition of 50% DDMF increased cookies' in-vitro protein digestibility, mineral contents, and fatty acids content. Thus, the nutritional quality of cookies concerning quantity and quality of protein and fat could be enhanced by incorporating DDMF.

Fermented mixed feed alters growth performance, carcass traits, meat quality and muscle fatty acid and amino acid profiles in finishing pigs

This study was conducted to investigate the effects of fermented mixed feed (FMF) on growth performance, carcass traits, meat quality, muscle amino acid and fatty acid composition and mRNA expression levels of genes related to lipid metabolism in finishing pigs. In the present study, 144 finishing pigs (Duroc × Berkshire × Jiaxing Black) were randomly allocated to 3 dietary treatments with 4 replicate pens per group and 12 pigs per pen. The dietary treatments included a basal diet (CON), a basal diet + 5% FMF and a basal diet + 10% FMF. The experiment lasted 38 d after 4 d of acclimation. The results showed that 5% and 10% FMF significantly increased the average daily gain (ADG) of the females but not the males (P < 0.05), but FMF supplementation showed no impact on carcass traits. Moreover, 10% FMF supplementation increased the meat color_45 min and meat color_24 h values, while it decreased the shear force relative to CON (P < 0.05). In addition, 10% FMF significantly increased the contents of flavor amino acids (FAA), total essential AA (EAA), total non-EAA (NEAA) and total AA relative to CON (P < 0.05). Furthermore, the diet supplemented with 10% FMF significantly increased the concentration of n-3 polyunsaturated fatty acids (PUFA), n-6 PUFA and total PUFA, and the PUFA to saturated fatty acids ratio (P < 0.05), suggesting that FMF supplementation increased meat quality. Moreover, compared with the CON, 10% FMF supplementation increased the mRNA expression of lipogenic genes, including CEBPα, PPARγ, SREBP1 and FABP4, and upregulated the expression of unsaturated fatty acid synthesis (ACAA1 and FADS2). Together, our results suggest that 10% FMF dietary supplementation improved the female pigs' growth performance, improved the meat quality and altered the profiles of muscle fatty acids and amino acids in finishing pigs. This study provides a reference for the production of high-quality pork.

Integrative analysis of transcriptomics and proteomics of longissimus thoracis of the Hu sheep compared with the Dorper sheep

Meat quality is becoming more important for sheep breeding programs. Meat quality is a complex trait affected by genetic and environmental factors. In the present study, an integrative analysis of the longissimus thoracis tissue transcriptome and proteome was conducted to identify genes, proteins, and pathways related to meat quality in sheep. The sheep breeds Hu and Dorper were considered. These breeds were compared for the differences in muscle fiber structure, chemical composition, and amino acid composition. In the Hu sheep vs. Dorper sheep comparison, 22 DEGs/DEPs showed the same mRNA and protein expression trends. These genes are associated with lipid transport, lipid metabolism, and muscular system development. Moreover, some pathways such as "lipid transport", "lipoprotein metabolic process", "Alanine, aspartate and glutamate metabolism", and "Arginine biosynthesis" were significantly enriched in this study. The reliability of the RNA-Seq results was verified by qRT-PCR. These findings provide new insights into the molecular mechanisms of meat quality in sheep.

Nutritional properties and amino acid profile of buckwheat bread

The effect of replacement of wheat flour with buckwheat flour at levels of 10, 20, 30, 40, and 50% on nutritional, texture, and physicochemical characteristics of bread was studied. Among others, parameters such as amino acid profile, antioxidant properties, and inositol phosphate content were determined. Amino acid score was calculated in order to evaluate the biological value of the bread protein. The breads with buckwheat flour were characterized by significantly lower whiteness of the crumb, compared to wheat bread. A positive effect of 10, 20, and 30% buckwheat flour content on the reduction of the crumb hardness, gumminess, chewiness was observed in comparison to other bread samples. A positive effect of buckwheat flour in the amount of 10-30% on the texture parameters and slowing down the process of bread staling was observed. The antioxidant properties and inositol phosphates increased with the share of buckwheat flour in the formula. A significant increase in protein was observed in bread from 20% share of buckwheat flour. The limiting amino acid of the protein of the tested flours and breads was lysine. For wheat bread, the amino acid score was 44.71% and for those with buckwheat flour it ranged from 45.67 to 75.38%.

Protein composition, chlorophyll, carotenoids, and cyanide content of cassava leaves (Manihot esculenta Crantz) as influenced by cultivar, plant age, and leaf position

The variation of proximate compositions, amino acids, carotenoids, chlorophyll, and total cyanide contents in cassava leaves was studied to identify the most suitable leaves for human consumption. The cassava leaves from 4 cultivars were analysed at 3 leaf positions as well as at 2 plant ages. The leaves of 'Rayong 5' cultivar from the middle position at 6 months after planting contained the highest crude protein, amino acids, carotenoids, and chlorophyll. The total cyanide content was high and therefore, an effective detoxification method is needed. Protein from the cassava leaves was rich in glutamine, aspartic acid, and leucine, but low in methionine and cysteine. Additionally, cassava leaves were found to be a rich source of carotenoids and chlorophyll. This study provided the evidences that cassava leaves can be an alternative source as protein supplement and for carotenoids and chlorophyll extraction and paves the way to valorise this abundant agricultural by-product.

Edible pectin film added with peptides from jackfruit leaves obtained by high-hydrostatic pressure and pepsin hydrolysis

Jackfruit (Artocarpus heterophyllus Lam.) is an evergreen tree that produces a high waste of leaves. This study evaluated the obtention of peptides from jackfruit leaves using pancreatin and pepsin, their antifungal activity, and their effect on pectin films. The protein content was 7.64 ± 0.12 g/100 g of jackfruit fresh leaves. Pancreatin produced a higher yield than pepsin in the obtention of peptides (p ≤ 0.05). However, peptides obtained after 2 h by pepsin hydrolysis (Pep-P) had six essential amino acids and inhibited > 99% of mycelial growth and spore germination of Colletotrichum gloeosporioides. Pectin films with Pep-P showed a slight brown color, lower thickness, water vapor permeability, and moisture content, as well as higher thermal stability and better inhibition properties against C. gloeosporioides than pectin films without Pep-P (p ≤ 0.05). Pectin films added with Pep-P from jackfruit leaf could be a green alternative to anthracnose control in tropical fruits.

Systematic investigation of the amino acid profiles that are correlated with xanthine oxidase inhibitory activity: Effects, mechanism and applications in protein source screening

This study aimed to investigate the dipeptide amino acid profiles correlated with xanthine oxidase (XOD) inhibitory activity and guide screening to determine suitable sources for XOD inhibitor protein hydrolysate preparation. The XOD inhibitory activities of 400 dipeptides were predicted via molecular docking and measured in vitro, and amino acids containing aromatic structures and charged residues were correlated with high XOD inhibitory properties. Subsequently, the effects of Cys-Glu and Lys-Glu, which showed the highest in vitro activities, were examined in hyperuricaemic mice, and were found to alleviate hyperuricaemia and modulate the gut microbiota. Furthermore, a suitable protein from Oreochromis mossambicus with high contents of charged (8.6%) and aromatic (1.67%) amino acids was screened, and the in vitro inhibitory rates of protein hydrolysate prepared from O. mossambicus against XOD were found to be 21.90% and 44.51% at 40 and 100 mg/ml, respectively. This study provides a strategy for screening protein hydrolysate sources with certain activities based on amino acid profiles.

Lower pollen nutritional quality delays nest building and egg laying in Bombus terrestris audax micro-colonies leading to reduced biomass gain

The performance of Bombus terrestris micro-colonies fed five diets differing in pollen species composition and level of nine essential amino acids (EAA; leucine, lysine, valine, arginine, isoleucine, phenylalanine, threonine, histidine, methionine) was assessed for 37 days by recording total biomass gain, nest building initiation, brood production (eggs, small and large larvae, pupae, drones), nectar, and pollen collection. Stronger colony performance was linked to higher amino acid levels but no consistent differences in biomass gain were recorded between mono- and poly-species diets. Poorest performance occurred in micro-colonies offered pure oilseed rape (OSR) pollen which contained the lowest EAA levels. Reduced micro-colony development (delayed nest initiation and lower brood production) was related to OSR proportion in the diet and lower EAA levels. Results are discussed in relation to selection of plant species in the design of habitats to promote bee populations.

Influence of cooking methods on antinutritional factors, oligosaccharides and protein quality of underutilized legume Macrotyloma uniflorum

Macrotyloma uniflorum is a salubrious but underutilized legume mainly consumed in semi-arid zones of Africa, Australia and India. Various antinutritional factors- phytates, oxalates and oligosaccharides- has limited its consumption. Current work describes the influence of various thermal processing technologies - autoclaving, microwave, micronization and extrusion- on antinutritional profile, phenolic acid profile and protein digestibility of two selected varieties. Significant (p ≤ 0.05) reduction in antinutritional content was observed for horse gram grains processed using various thermal technologies. Among all processing technologies extrusion caused marked degradation in antinutritional components. The reduction in oxalic acid, trypsin inhibitor, phytates and tannins ranged from 33 to 87 %, 77-82%, 33-60% and 51-66% respectively. Further, the decline in content of various oligosaccharides viz. raffinose, stachyose and verbascose varied from 36 to 61 %, 25-49% and 30-74% respectively for both the varieties. Although extrusion caused significant (p ≤ 0.05) decrease in the essential amino acid index and protein efficiency ratio, simultaneous increased was observed in biological value. The processing had significant (p ≤ 0.05) impact on grain antinutritional content and also retained its substantial functional properties. This establishes the utility of grain and promote the introduction of these new grains and enlarge the market of novel healthy foods.

Development of co-culture yeast fermentation for efficient production of biobutanol from rice straw: A useful insight in valorization of agro industrial residues

Escalating environmental concerns and petroleum demands leads into the present study. In this investigation delignification of rice straw was optimized by NaOH and H2SO4 pretreatment using L16 Taguchi orthogonal array. NaOH pretreatment revealed higher delignification as compared to H₂SO₄ and; further subjected to separate enzymatic hydrolysis and co-fermentation (SHCF) using RSM as the SHCF demonstrated a maximum glucose and xylose yield of 575 and 205 mg/g. Further, butanol concentration of 4.32 g/L was achieved from 20 g/L of sugar loadings by co-culture of Saccharomyces cerevisiae and Pichia sp. at 72 h of incubation time which was 79.25% higher as compared to monocultures of Pichia sp. Scale-up experiments with higher sugar loadings (90 g/L) demonstrated a butanol concentration of 13.3 g/L. The release of amino acids in co-culture and monoculture systems demonstrated that the addition of S. cerevisiae promoted the butanol synthesis pathway which led to higher butanol concentration.

Plasma free amino acid profiling as metabolomic diagnostic and prognostic biomarker in paediatric cancer patients: a follow-up study

Amino acids (AAs) play a crucial role in cancer cell metabolism. Levels of 22 plasma AAs at the time of diagnosis and after treatment were established among 39 pediatric cancer patients and 33 healthy children. Glutamic acid levels decreased and tryptophan levels increased during treatment. Cancer patients presented significantly lower levels of glutamine and leucine post-treatment while levels of 12 other AAs were higher comparing to controls. Results suggest that plasma free AA profile may serve as a prognostic biomarker.

infection and dietary inclusion of arginine on intestine histological parameters, serum amino acid profile and ileal amino acids digestibility in broiler chicks

Coccidiosis is considered to be one of the most important challenge in the poultry industry causes economic losses due to the destruction in the digestive tract of chicken. It disturbs amino acids profile and their digestibility, leading to weight lost and economic burden. Using dietary arginine may decrease the adverse effects of coccidiosis on chicken digestive tract. This study aimed to evaluate the effects of dietary inclusion of arginine on intestine histological parameters, serum amino acid concentration and ileal amino acid digestibility of broiler chicks infected with coccidiosis. A total number of 384 one-d-old broiler chicks (Ross 308) of mixed sex with initial weight of 42 ± 2 g was allocated into 8 groups with 8 birds/pen from grower period. At 21 days of age, broiler chicks were infected with a mixture of Eimeria spp. Broiler chicks were divided into infected and un-infected groups and received arginine at recommended levels of 85, 100, 125 and 150 %. Intestinal morphology and lesions, serum amino acid concentration and ileal amino acid digestibility were evaluated. Broiler chicks infected with Eimeria spp. showed lower villus height and villus height: crypt depth ratio and also higher intestinal lesions (P < 0.05). Coccidia infection decreased the ileal amino acid digestibility for all studied amino acids and also reduced serum concentrations of amino acids, except lysine and isoleucine (P < 0.05). Dietary supplementation of arginine especially in higher levels significantly increased villus height and villus height:crypt depth ratio and decreased lesions (P < 0.05). Moreover, dietary supplementing of arginine increased the serum concentration of arginine (P < 0.05), but it did not have any significant effect on its digestibility (P > 0.05). In sum, coccidiosis decreases amino acid digestibility and serum amino acid concentration, but dietary inclusion of higher levels of arginine significantly improved histological parameters of broiler chicks infected with coccidiosis.

Different dietary starch sources alter the carcass traits, meat quality, and the profile of muscle amino acid and fatty acid in finishing pigs

BACKGROUND

With increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis (L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen. Tapioca starch (TS), corn starch (CS), and pea starch (PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44, respectively, were used as their dietary starch sources for 40 days.

RESULTS

Results showed that the PS diet significantly increased (P < 0.05) the final body weight, average daily gain, loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased (P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased (P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased (P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased (P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid (PUFA) in the L. thoracis compared with TS diet, but decreased (P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated (P < 0.05) the lipogenic genes (FAS, LPL, SCD, ACCα) and myosin heavy-chain (MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated (P < 0.05) the CPT1B and MyHC-IIb mRNA levels.

CONCLUSIONS

In conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork.

AMPK-mTOR pathway is involved in glucose-modulated amino acid sensing and utilization in the mammary glands of lactating goats

Background

The local supply of energy-yielding nutrients such as glucose seems to affect the synthesis of milk components in the mammary gland (MG). Thus, our study was conducted to investigate the effects of locally available MG glucose supply (LMGS) on amino acid (AA) sensing and utilization in the MG of lactating dairy goats. Six dosages of glucose (0, 20, 40, 60, 80, and 100 g/d) were infused into the MG through the external pudendal artery to investigate the dose-dependent changes in mammary AA uptake and utilization (Exp.1) and the changes in mRNA and protein expression of the AMPK-mTOR pathway (Expt.2).

Results

In Exp.1, total milk AA concentration was highest when goats were infused with 60 g/d glucose, but lower when goats were infused with 0 and 100 g/d glucose. Increasing LMGS quadratically changed the percentages of α_S2-casein and α-lactalbumin in milk protein, which increased with infusions from 0 to 60 g/d glucose and then decreased with infusions between 60 and 100 g/d glucose. The LMGS changed the AA availability and intramammary gland AA utilization, as reflected by the mammary AA flux indexes. In Exp.2, the mRNA expression of LALBA in the MG increased quadratically with increasing LMGS, with the highest expression at dose of 60 g/d glucose. A high glucose dosage (100 g/d) activated the general control nonderepressible 2 kinase, an intracellular sensor of AA status, resulting in a reduced total milk AA concentration.

Conclusions

Our new findings suggest that the lactating MG in dairy goats may be affected by LMGS through regulation of the AA sensory pathway, AA utilization and protein synthesis, all being driven by the AMPK-mTOR pathway.

Effect of protein during hydrothermal carbonization of brewer's spent grain

This study has two targets: Studying the extraction of the initial protein content from brewer's spent grain and the impact of protein's extraction on the chemical-physical properties of produced hydrochars. The protein was extracted from brewer's spent grains using the pH-shifting method. The extracted protein was quantified and characterized by their amino acid profile. The hydrothermal treatment was applied at 190 °C and 220 °C for 0.5 h, 1 h, 2 h, and 4 h. The hydrochars and process water were collected and assayed. The hydrochar after protein extraction reveals the lowest yield to hydrochars (67.10-45.14%), higher C/N ratio (19.66-21.33) and lower ash content (1.52-1.72 wt%) compared to the hydrochar without extraction.

Improvement of the characteristics of fish gelatin - gum arabic through the formation of the polyelectrolyte complex

The aim of this study was to evaluate and characterize the interaction between fish gelatin (FG) and Gum Arabic(GA) and its effects in obtaining optimal atomization conditions. The optimal conditions (D = 0.866) founded in this paper were: Gum Arabic concentration of 33.4% and inlet air temperature of 130 °C. These conditions afforded 6.62 g/h yield, 0.27 a_w and 247 g of Gel Strength, that are considered as suitable characteristics for food grade gelatin. The complex formed (FG-GA) was successfully obtained, as demonstrated by the results of amino acid profile, SDS-PAGE, FTIR spectroscopy, zeta potential and morphology. It was also verified that the formation of FG-GA promotes positive changes, such as higher atomization yield, adequate Gel Strength, low hygroscopicity and high solubility. The technological properties of FG-GA shown high potential to be applied in the food industry as well in other industrial fields like chemical and pharmaceutical areas.

Marine lizardfish (Harpadon nehereus) meal concentrate in preparation of ready-to-eat protein and calcium rich extruded snacks

Bombay duck (Harpadon nehereus) a high protein fish, is one of the significant estuarine fish of the West Coast of India. Apart from being rich in protein the fish is also a store house of important minerals. This study was conducted to determine the physicochemical properties of the fish meal and utilize it to produce protein rich extruded snacks by twin screw extrusion technology at optimized parameters of 110 °C temperature, 16% moisture and 350 RPM screw speed. Protein of the fish meal concentrate was found to be around 54 g/100 g, mineral content particularly calcium around 2100.32 mg/100 g, phosphorous 240 mg/100 g and substantial amount of potassium, sodium, iron and zinc. Amino acid profile revealed presence of some essential amino acids. 1-D gel electrophoresis showed presence of low and medium kDa proteins ranging between 10 and 50 kDa. Functional and physicochemical property studies of extrudates revealed that 15% fish meal incorporation gave highest expansion ratio of 3.46. Addition of Bombay duck fish meal to extruded snack preparations had resulted in good taste and texture. The protein contents of the products ranged from 9.35 to 21.00 g/100 g. The results indicated that fish meal can be useful for preparing low cost protein rich food.

Influence of multigrain premix on nutritional, in-vitro and in-vivo protein digestibility of multigrain biscuit

Effect of addition of multigrain premix (MGP) prepared using a combination of cereals, pulses and oilseeds at 40% level, on nutritional properties of multigrain biscuit, its in-vitro and in-vivo protein digestibility and protein profiling were studied. The incorporation of MGP significantly increased the protein content (from 7.37 to 16.61%), insoluble dietary fiber (from 1.71 to 6.67%), soluble dietary fiber (from 0.46 to 2.42%). The significant increase in the levels of isoleucine (ND-34.79%), methionine (0.04 to 7.65%), tryptophan (0.22 to 5.95%) valine (0.38 to 16.58%), lysine (0.36 to 7.32%), and threonine (0.51 to 7.2%) was observed, whereas fatty acid profile of MGP incorporated biscuits showed increased polyunsaturated fatty acids and decreased saturated fatty acids. The vitamin-mineral profile of MGP incorporated biscuits showed increased the thiamin (0.07-0.21 mg/100 g), riboflavin (0.09-0.28 mg/100 g), calcium (12.89-45.28 mg/100 g) and iron (1.13-3.47 mg/100 g) contents. The in-vitro protein digesibility of multigrain and control biscuits indicated that the proteins present in multigrain biscuits had high digestibility (71.73%) as compared to control biscuit (38.13%). The in-vivo studies indicated that, the protein quality of multigrain biscuits was comparable with casein protein with high protein efficiency ratio of 3.02. The electrophoretic pattern of multigrain biscuits showed subunit molecular weight distribution of different protein units and aggregation of protein bands at high molecular weight region of 85 to 166 kD. The outcome of the study indicated the possibility of utilising MGP to improve the overall nutritional quality of biscuits.

Discrepant effects of copper (II) stress on different types of skeletal muscles in chicken: Elements and amino acids

Different distributions of 28 elements and 17 amino acids in pectoralis, wing biceps brachii and leg gastrocnemius of chicken upon CuSO₄ (300 mg/kg) exposure for 90 days were investigated. Accompanied by copper accumulation, pathological injuries were observed in those three kinds of skeletal muscles using histological and ultrastructural methods. Based on data obtained, we analyzed leg gastrocnemius displayed the most increases (P < 0.000) in all three kinds of elements detected, including macroelements (131%), essential microelements (129%) and toxic microelements (179%) than the other two skeletal muscles. Furthermore, decreased total amino acids (P = 0.006), a susceptibility of lipid peroxidation/oxidative stress and a disequilibrium of nutrition and taste were analyzed in the leg gastrocnemius, indicating an unsuitability for human consumption. Intriguingly, these anomalies were scarce in pectoralis and wing biceps brachii. Combined with multivariate analysis we may conclude that leg gastrocnemius are more vulnerable to copper stress than pectoralis and wing biceps brachii in chicken.

Numerical analysis of intracellular amino acid profiles of breast cancer cells with K-Ras or PI3K mutation in response to kinase inhibitors

BACKGROUND

Various efforts to understand the relationship between biological information and disease have been done using many different types of highthroughput data such as genomics and metabolomics. However, information obtained from previous studies was not satisfactory, implying that new direction of studies is in need. Thus, we have tried profiling intracellular free amino acids in normal and cancerous cells to extract some information about such relationship by way of the change in IFAA levels in response to the treatment of three kinase inhibitors. We define two measures such as relative susceptibility (RS) and relative efficacy (RE) to numerically quantify susceptibility of cell line to treatment and efficacy of treatment on cell line, respectively.

METHODS

We applied principal component analysis (PCA) to the intracellular free amino acids (IFAAs) of isogenic breast cells with oncogenic mutation in K-Ras or PI3K genes to investigate the change in IFAA levels in response to the treatment of three kinase inhibitors. Two-dimensional plot, which was graphically represented by using the first two principal components (PCs), enabled us to evaluate the treatment efficacy in cancerous cells in terms of the quantitative distance of two IFAA profiles from cancerous and normal cells with the same treatment condition.

RESULTS

The biggest change in metabolic states in K-Ras mutant cell was caused by REGO for both treatment time (RS=2.31 (24 h) and 1.64 (48 h)). Regarding RE, REGO was the most effective on K-Ras/PI3K mutant cell line for treatment time 24h (RE=1.28) while PI3K inhibitor had good effect on K-Ras mutant cell line for 48h (RE=1.1).

CONCLUSIONS

Numerical study on the link between amino acid profile and cancer has been done in two different dimensions. We then summarized such link in terms of two new metrics such as RS and RE, which we first define in this work. Although our study based on those metrics seems to work, we think that the usefulness of the metrics in cancer study of this kind need to be further investigated.

Effects of pulses and microalgal proteins on quality traits of beef patties

Physicochemical parameters (pH, colour and texture), proximate composition (moisture, protein, lipid and ash content), amino acid content, and taste profile of beef patties elaborated with soy (control), pulses (pea, lentil and bean) and microalgal (Chlorella and Spirulina) proteins were assessed. The pH, colour, ash content, total, essential and non-essential amino acids and amino acid content were significantly different among the beef patties studied. In this regard, beef patties prepared with pea protein presented the highest values for pH; whereas beef patties manufactured with pea also showed the highest values for lightness and patties elaborated with bean the highest values for redness. Similar textural parameters were observed among the six batches of beef patties manufactured. Regarding ash content, a significant higher content was observed in the beef patties prepared with soy compared to the other ones. On the other hand, the beef patties elaborated with bean and seaweeds showed the highest values for the total amino acids content. The inclusion of bean and seaweed proteins increased the concentrations of all amino acids in beef patties, being glutamic acids, lysine and aspartic acid the predominant amino acids. Regarding the taste analysis, a similar profile was found among the six batches of beef patties studied. Considering all studied parameters, beef patties elaborated with bean protein could be used as an alternative protein source respect to soy protein because of it showed a similar nutritional content and taste profile and higher amino acid content.

Effect of different processing conditions on proximate composition, anti-oxidants, anti-nutrients and amino acid profile of grain sorghum

The effect of different processing conditions (B: boiling; F: LAB fermentation; FS: fermentation and steaming; FSF: fermentation, steaming, flaking) of whole grain sorghum on the proximate composition, antioxidants, anti-nutrients, and amino acids (AAs) was evaluated. A marginal increase in the protein content and a decrease in the fat content was observed in the F-sample. Total phenolics reduced by 28%; DPPH scavenging activity and CUPRAC activity increased by 1.4 and 6 times, respectively during fermentation. Tannin content reduced by 30-39%, for the F, FS and FSF samples; highest reduction in trypsin inhibitory activity (58%) was observed in the FS-sample. Total AAs increased by 2.9 folds in FSF samples. Grain sorghum contained mostly hydrophobic AAs (30-34%). The ratio of Essential amino acid to total amino acid and predicted protein efficiency ratio were highest in the F-sample, whereas predicted biological value of the FSF was 3 times than that of the control.

Impact of the soy protein replacement by legumes and algae based proteins on the quality of chicken rotti

The addition of different protein sources (soy, bean, lentil, broad bean, Spirulina, and Chlorella) on nutritional, physicochemical and sensory properties of chicken rotti was evaluated. Significant changes were observed in physicochemical composition, textural properties and amino acid content of chicken rotti after adding the proteins from different sources, thus influencing the sensory acceptance and preference. Spirulina and Chlorella rotti presented a slight increase of pH and seaweed caused a decrease in some colour parameters. The highest lipids contents were found in chicken rotti added of with Spirulina and lentil proteins. Chicken rotti prepared with lentil protein also showed the highest values for ash content. Chicken rotti enriched with seaweed protein presented the highest total amino acid content. Principal component analysis showed that broad beans and lentils proteins as interesting ingredients to replace soy protein in chicken rotti.

NMR-based metabolic study of fruits of Physalis peruviana L. grown in eight different Peruvian ecosystems

The berry of Physalis peruviana L. (Solanaceae) represents an important socio-economical commodity for Latin America. The absence of a clear phenotype renders it difficult to trace its place of origin. In this study, Cape gooseberries from eight different regions within the Peruvian Andes were profiled for their metabolism implementing a NMR platform. Twenty-four compounds could be unequivocally identified and sixteen quantified. One-way ANOVA and post-hoc Tukey test revealed that all of the quantified metabolites changed significantly among regions: Bambamarca I showed the most accumulated significant differences. The coefficient of variation demonstrated high phenotypic plasticity for amino acids, while sugars displayed low phenotypic plasticity. Correlation analysis highlighted the closely coordinated behavior of the amino acid profile. Finally, PLS-DA revealed a clear separation among the regions based on their metabolic profiles, accentuating the discriminatory capacity of NMR in establishing significant phytochemical differences between producing regions of the fruit of P. peruviana L.

A window into extreme longevity; the circulating metabolomic signature of the naked mole-rat, a mammal that shows negligible senescence

Mouse-sized naked mole-rats (Heterocephalus glaber), unlike other mammals, do not conform to Gompertzian laws of age-related mortality; adults show no age-related change in mortality risk. Moreover, we observe negligible hallmarks of aging with well-maintained physiological and molecular functions, commonly altered with age in other species. We questioned whether naked mole-rats, living an order of magnitude longer than laboratory mice, exhibit different plasma metabolite profiles, which could then highlight novel mechanisms or targets involved in disease and longevity. Using a comprehensive, unbiased metabolomics screen, we observe striking inter-species differences in amino acid, peptide, and lipid metabolites. Low circulating levels of specific amino acids, particularly those linked to the methionine pathway, resemble those observed during the fasting period at late torpor in hibernating ground squirrels and those seen in longer-lived methionine-restricted rats. These data also concur with metabolome reports on long-lived mutant mice, including the Ames dwarf mice and calorically restricted mice, as well as fruit flies, and even show similarities to circulating metabolite differences observed in young human adults when compared to older humans. During evolution, some of these beneficial nutrient/stress response pathways may have been positively selected in the naked mole-rat. These observations suggest that interventions that modify the aging metabolomic profile to a more youthful one may enable people to lead healthier and longer lives.

Determination of the authenticity of plastron-derived functional foods based on amino acid profiles analysed by MEKC

Plastron is a nutritive and superior functional food. Due to its limited supply yet enormous demands, some functional foods supposed to contain plastron may be forged with other substitutes. This paper reports a novel and simple method for determination of the authenticity of plastron-derived functional foods based on comparison of the amino acid (AA) profiles of plastron and its possible substitutes. By applying micellar electrokinetic chromatography (MEKC), 18 common AAs along with another 2 special AAs - hydroxyproline (Hyp) and hydroxylysine (Hyl) were detected in all plastron samples. Since chicken, egg, fish, milk, pork, nail and hair lacked of Hyp and Hyl, plastron could be easily distinguished. For those containing collagen, a statistical analysis technique - principal component analysis (PCA) was adopted and plastron was successfully distinguished. When applied the proposed method to authenticate turtle shell glue in the market, fake products were commonly found.

Assessment of the functional properties of protein extracted from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray

A protein extract from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray was prepared and its functional properties, colour and amino acid composition were assessed for its potential future use by the food industry. The total content of amino acids was determined as 54.02±0.46gaminoacids/kg dry weight, with high levels of the essential amino acids lysine and methionine. SDS-PAGE showed 5 protein bands with molecular weights of 71.6, 53.7, 43.3, 36.4 and 27.1kDa. The water holding capacity and oil holding capacity were determined as 10.27±0.09gH2O/g and 8.1±0.07goil/g respectively. Foaming activity and stability were higher at alkaline pH values. The emulsifying capacity and stability of the extract varied depending on the pH and oil used. These results demonstrate the potential use of Himanthalia elongata protein extract in the food industry.

Effect of acid pretreatment and the germination period on the composition and antioxidant activity of rice bean (Vigna umbellata)

This research evaluated effect of germination period and acid pretreatment on chemical composition and antioxidant activity of rice bean sprouts. Moisture, total phenolics, reducing sugar and B vitamins (thiamine, riboflavin, and niacin) content of steamed sprouts increased with increasing germination time (p⩽0.05). Pretreatment with 1% (w/v) citric acid for 6h significantly increased the total phenolic content. The 18-h-germinated rice beans showed the highest crude protein content, as determined using the Kjeldahl method. During germination, acid pretreatment led to a significant decrease in the intensity of the 76-kDa band. Germination caused a significant increase in radical scavenging activity and ferric reducing antioxidant power, especially in sprouts from citric acid-treated seeds. The antioxidant activities of the ethanolic extracts from both pretreated beans and the control were 1.3-1.6 times higher than those obtained from the water extracts. Major phenolics found in both 0-h and 18-h-germinated rice beans were catechin and rutin.

Short-term supplementation of isocaloric meals with L-tryptophan affects pig growth

L-Tryptophan (Trp) and some of its metabolites regulate the circadian rhythm in mammals. We aimed to investigate the effects of short-term supplementation of Trp in isocaloric meals on growth performance using the parameters of multiple blood biomarkers and free amino acids in growing pigs. A total of 32 Landrace × Yorkshire barrows with a mean body weight of 8.64 (±1.13) kg were randomly assigned to four groups and then fed with various concentrations of Trp diets daily. Our results showed that sequential supplementation of different concentrations of Trp in isocaloric meals decreased the feed:gain (F:G) ratio (P = 0.079) and plasma urea and albumin (P = 0.019), whereas the level of total protein did not. Among the essential and conditionally essential amino acids, the concentrations of histidine, isoleucine, proline, threonine, arginine, and valine in the plasma decreased (P < 0.05), whereas the concentrations of Trp, glycine, serine, and methionine increased (P < 0.01). In addition, concentrations of branched chain amino acids also significantly decreased (P = 0.004), while the rate of conversion of Trp to branched chain amino acids increased (P < 0.001). Taken together, we show that administration of a high concentration of Trp in breakfast with decreasing concentrations of Trp in lunch and dinner positively affected feed utilization and improved feed efficiency, at least in part, through the optimization of amino acid interconversions and nitrogen utilization.

Optimization of production and quality evaluation of maize-based snack supplemented with soybean and tiger-nut (Cyperus esculenta) flour

Optimization of the production and evaluation of the quality of maize-based snack supplemented with soy and tigernut flour was carried out. Experimental design for the composite flour was carried out using optimal design model of response surface methodology. The variables were toasted maize flour (75-85%), soy flour (10-20%), and tigernut flour (5-10%); while the responses were proximate composition and mineral contents. Three blends were selected from optimization results; runs 2, 7, and 11. The functional properties, pasting properties, antioxidant, antinutritional, and amino acid profile of the three blends were evaluated. In addition, sensory evaluation of the cookies produced from the three blends was determined. The results (75/100 g toasted maize flour, 20/100 g soy flour, and 5/100 g tigernut flour) had 16.4/100 g protein, 4.2/100 g ash, 3.5/100 g moisture, 58.5/100 g carbohydrate, 3.0/100 g crude fiber, 14.4/100 g fat, 30.20 ppm calcium, 38.90 ppm potassium, 0.25 ppm manganese, 1.91 ppm iron, 0.14 ppm copper, and 0.98 ppm zinc contents. It also had best overall acceptability.

Effects of dietary lysine levels on plasma free amino acid profile in late-stage finishing pigs

Muscle growth requires a constant supply of amino acids (AAs) from the blood. Therefore, plasma AA profile is a critical factor for maximizing the growth performance of animals, including pigs. This research was conducted to study how dietary lysine intake affects plasma AA profile in pigs at the late production stage. Eighteen crossbred (Large White × Landrace) finishing pigs (nine barrows and nine gilts; initial BW 92.3 ± 6.9 kg) were individually penned in an environment controlled barn. Pigs were assigned randomly to one of the three dietary treatments according to a randomized complete block design with sex as block and pig as experiment unit (6 pigs/treatment). Three corn- and soybean meal-based diets contained 0.43 % (lysine-deficient, Diet I), 0.71 % (lysine-adequate, Diet II), and 0.98 % (lysine-excess, Diet III) l-lysine, respectively. After a 4-week period of feeding, jugular vein blood samples were collected from the pigs and plasma was obtained for AA analysis using established HPLC methods. The change of plasma lysine concentration followed the same pattern as that of dietary lysine supply. The plasma concentrations of threonine, histidine, phenylalanine, isoleucine, valine, arginine, and citrulline of pigs fed Diet II or III were lower (P < 0.05) than that of pigs fed Diet I. The plasma concentrations of alanine, glutamate, and glycine of pigs fed Diet II or III were higher (P < 0.05) than that of pigs fed Diet I. The change of plasma leucine and asparagine concentrations followed the patterns similar to that of plasma lysine. Among those affected AAs, arginine was decreased (P < 0.05) in the greatest proportion with the lysine-excess diet. We suggest that the skeletal muscle growth of finishing pigs may be further increased with a lysine-excess diet if the plasma concentration of arginine can be increased through dietary supplementation or other practical nutritional management strategies.

Obesity-related metabolite profiles of black women spanning the epidemiologic transition

In developed countries, specific metabolites have been associated with obesity and metabolic diseases, e.g. type 2 diabetes. It is unknown whether a similar profile persists across populations of African-origin, at increased risk for obesity and related diseases. In a cross-sectional study of normal-weight and obese black women (33.3 ± 6.3 years) from the US (N = 69, 65 % obese), South Africa (SA, N = 97, 49 % obese) and Ghana (N = 82, 33 % obese) serum metabolite profiles were characterized via gas chromatography-time of flight/mass spectrometry. In US and SA women, BMI correlated with branched-chain and aromatic amino acids, as well as dopamine and aminoadipic acid. The relationship between BMI and lipid metabolites differed by site; BMI correlated positively with palmitoleic acid (16:1) in the US; negatively with stearic acid (18:0) in SA, and positively with arachidonic acid (20:4) in Ghana. BMI was also positively associated with sugar-related metabolites in the US; i.e. uric acid, and mannitol, and with glucosamine, glucoronic acid and mannitol in SA. While we identified a common amino acid metabolite profile associated with obesity in black women from the US and SA, we also found site-specific obesity-related metabolites suggesting that the local environment is a key moderator of obesity.

Integrated bioethanol and protein production from brown seaweed Laminaria digitata

A wild-growing glucose-rich (i.e. 56.7% glucose content) brown seaweed species Laminaria digitata, collected from the North Coast of Denmark in August 2012, was used as the feedstock for an integrated bioethanol and protein production. Glutamic acid and aspartic acid are the two most abundant amino acids in the algal protein, both with proportional content of 10% in crude protein. Only minor pretreatment of milling was used on the biomass to facilitate the subsequent enzymatic hydrolysis and fermentation. The Separate Hydrolysis and Fermentation (SHF) resulted in obviously higher ethanol yield than the Simultaneous Saccharification and Fermentation (SSF). High conversion rate at maximum of 84.1% glucose recovery by enzymatic hydrolysis and overall ethanol yield at maximum of 77.7% theoretical were achieved. Protein content in the solid residues after fermentation was enriched by 2.7 fold, with similar distributions of amino acids, due to the hydrolysis of polymers in the seaweed cell wall matrix.

Investigation of salivary free amino acid profile for early diagnosis of breast cancer with ultra performance liquid chromatography-mass spectrometry

BACKGROUND

Breast cancer (BC) is the second leading cause of cancer death in women worldwide. This study aimed at investigating salivary free amino acid (SFAA) profile to facilitate the early diagnosis of BC.

METHODS

Unstimulated whole saliva from BC patients (n=27) and randomly from healthy females (n=28) were assayed with ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic performance of each of the amino acid (AA) biomarkers, or SFAA profile index for BC screening.

RESULTS

Concentrations of 15 SFAAs demonstrated significant differences (P<0.05) between BC patients at stages I-II and healthy controls (HC). The area under the curve (AUC) values in HC vs BCs I-II based on single AA were from 0.695 to 0.866. The AUC for SFAA profile index combined Pro, Thr, His was 0.916 (sensitivity 88.2%, specificity 85.7%) in distinguishing HC from BCs I-II.

CONCLUSIONS

The diagnostic potentials of 15 SFAAs as early diagnostic biomarkers for BC were verified and the diagnostic accuracy was improved in the use of SFAA profile index. The detection of SFAA profile is expected to be applied for the preclinical screening of early stage of BC in the future.

Influence of the composition of unripe genipap (Genipa americana L.) fruit on the formation of blue pigment

The physical and chemical characteristics of unripe genipap fruits and the proximate and amino acid compositions of the endocarp and mesocarp of the unripe fruits were determined, placing special emphasis on the possible role of the protein-amino acid fraction on the formation of the typical blue pigment of the matrix. The two parts of the fruit analyzed have low energy (49.88 kcal/100 g for mesocarp and 43.48 kcal/100 g for endocarp) and high fiber content (7.88 % for mesocarp and 16.76 % for endocarp). The endocarp showed protein content (3.19 %) five times higher than the mesocarp (0.62 %), which may explain in part the greater amounts of blue pigment formed in the endocarp when compared to the mesocarp. Furthermore, the pH found in mesocarp (4.49) and endocarp (5.21) is within the optimum range for the formation of the blue pigment. A significant color change (ΔE (*)  = 26.45) was observed in endocarp during its exposure to the air for 2 h. Free aspartic and glutamic acids and cystine were the predominant amino acids in the mesocarp, while glutamic and aspartic acids and leucine were predominant in the endocarp. According to the results, the formation of blue pigment does not cause any change in the amino acid composition.

Compositional analysis of developed whey based fructooligosaccharides supplemented low- calorie drink

Array of evidences have indicated that the supplementation of diet with functional and nutritional components to provide numerous health benefits. In this context, fortification with novel constituents as prebiotics i.e. fructooligosaccharides (FOS) is an encouraging trend all over the world. In the current exploration, FOS was used as a prebiotic in whey based functional drinks. For drink formulation, four samples were prepared i.e. whey based drink (T1) and FOS supplemented whey drinks @ 0.5, 1.0 and 1.5 % referred as T2, T3 and T4, respectively. The formulated drinks were evaluated for compositional analysis with special reference to amino acids and mineral profiles. The functional drinks showed momentous impact on total solids (TS) whilst, pH, acidity, crude protein and fat were affected non-significantly. However, pH, TS, fat and protein contents of prepared drinks were decreased substantially (p < 0.05) during storage period. However, prepared drinks showed non-significant variations in essential and non-essential amino acids.