Fatty acid composition of egg yolk phospholipid fractions following feed supplementation of Lohmann Brown hens with humic-fat preparations

Interfacial composition in infant formulas powder modulate lipid digestion in simulated in-vitro infant gastrointestinal digestion

The interface structure and composition of fat globules are very important for the digestion and metabolism of fat and growth in infants. Interface composition of fat globules in infant formula (IF) supplemented with milk fat globule membranes (MFGM) and lecithin in different ways were analyzed and their effects on fat digestion properties were evaluated. The results showed that the distribution of phospholipids at the interface and structural of Concept IF1 and Concept IF2 that were more similar to those of human milk (HM) than that of conventionally processed IF3. Concept IF2 and IF3 supplemented with lecithin had larger initial particle size and more sphingomyelin (SM) (23.12 ± 0.26 %, 26.94 ± 0.34 %) than Concept IF1, and Concept IF2 had the smallest proportion of casein in the interfacial. Due to its interface composition, Concept IF2 had the highest degree of lipolysis (85.07 ± 0.76 %), the phospholipid ring structure can always be observed during gastric digestion, and a final fatty acid composition released that was more similar to HM. Concept IF1 and IF3 were different from HM and Concept IF2 in terms of structure and lipolysis rate, although superior to commercial IF4. These indicate that changes in the interfacial composition and structure of fat globules improve the digestive properties of fats in IF. Overall, the results reported herein are useful in designing new milk formulas that better simulate HM.

Multifarious feed additives on lamb performance on Kuwait farms

Background and Aim

A change in the livestock feeding strategy is of utmost importance for the stability of animal health and sustainable livestock productivity to overcome the problem of subsiding the environmental effects of sheep production. Supplementing dietary feed with safe and efficient additives provides optimal animal performance and maximizes productivity. This study aimed to assess the effects of adding various feed additives to lamb rations for optimizing feed efficiency in weaned lambs for meat production in Kuwait.

Materials and Methods

The feed additives, namely, ammonium chloride, urea, algae, fishmeal, and humic acid, were investigated on the physical performance of lambs for their effect on body weight, length, height, and waist length. The total feed consumption rate and feed efficiency were also measured. Each treatment comprising five healthy lambs was randomly allocated into six treatments comprising 30 lambs. The six treatments were the basal ration supplemented with ammonium chloride (50-100 g/day/head), urea (30 g/day/head), fishmeal (35 g/day/head), algae (Spirulina platensis) powder (50 g/day/head), humic acid (2.5 g/day/head), control group with only basal ration. The study was conducted for around 27 months and the data were recorded once in 2 weeks.

Results

The results indicated a positive elevation in the physique of lambs with all tested additives, showing an affirmative insignia for lamb fattening. The growth parameters in terms of augmented length, height, and waist length of lambs' bodies amplified significantly with ammonium chloride and fishmeal supplement, while the other additives reported a non-significant increment. The feed consumption was significantly elevated for ammonium chloride, algae, and fishmeal supplementation, while humic acid was recorded the least. Concerning feed efficiency of young lambs, fish meal and ammonium chloride were reported best, followed by urea. In contrast, algae and humic acid exhibited a non-significant effect on feed efficiency.

Conclusion

This study exposed noteworthy influence on a lamb body's performance with the addition of fish meal and ammonium chloride in lamb rations, trailed by urea and algae.

Effect of Rosemary Extract on Lipid Oxidation, Fatty Acid Composition, Antioxidant Capacity, and Volatile Compounds of Salted Duck Eggs

The purpose of our study was to determine the impact of rosemary extract in duck eggs, as determined by in vitro antioxidant capacity, lipid oxidation, fatty acid profiles, and flavor analyses. Three groups of salted duck eggs were compared: A control group and group enriched with 0.1% and 0.5% (w/v) rosemary extracts for 28 days of salting. In a time-dependent manner, the radical scavenging activity and reduction power of eggs with 0.5% (w/v) rosemary extract were significantly higher those of the control at 28 days after salting. The fatty acid profiles of salted egg were significantly affected by rosemary extract and salting time. Palmitic acid was the most abundant fatty acid in salted egg treated with rosemary extract, followed by linoleic acid and arachidonic acid. Furthermore, the treated eggs contained more docosahexaenoic acid than the control ones. And the treated eggs also have a considerable impact on the lipid oxidation process (primary and secondary oxidation). As a result, rosemary extract can be used as a natural antioxidant spice to prevent oxidation and extend the shelf life of eggs during storage. Furthermore, flavor research using solid phase microextraction - gas chromatography - mass spectrometry and an electronic nose demonstrated that adding rosemary extract to salted eggs could give them a distinct flavor.

Astaxanthin improved the storage stability of docosahexaenoic acid-enriched eggs by inhibiting oxidation of non-esterified poly-unsaturated fatty acids

This study assessed the potential and mechanism of action of astaxanthin, to improve the stability of docosahexaenoic acid (22:6(n-3); DHA) enriched egg products, during storage at 4 °C. The reduction in DHA content after 42 days of storage in astaxanthin-DHA eggs (from hens fed supplemental astaxanthin and DHA) was <3%, whereas the reduction in regular-DHA eggs (hens fed DHA only) was over 17%. Astaxanthin also decreased production of oxidation products including 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal and malondialdehyde in eggs during storage, thus markedly improving the oxidative stability of DHA-enriched eggs. The yolk lipidomic profile showed higher intensities for most DHA-containing lipids, especially DHA-phosphatidylcholine, DHA-phosphatidylethanolamine and DHA-non-esterified fatty acid, compared with regular-DHA eggs. Astaxanthin acts primarily by suppressing oxidation of DHA-non-esterified fatty acid, which minimizes the degradation of DHA and appears to be the primary protection mode of yolk DHA during storage.

Fatty acid compositions and quality of egg and performance in laying quails fed diet with hesperidin

This study investigates the effects of hesperidin on eggs' internal and external quality parameters, the fatty acid in egg yolk, and the nutrient content adding different amounts of hesperidin to the quail diets. A total of 150 Japanese quails (Coturnix coturnix japonica) were divided into three groups (0% hesperidin group (n = 5 × 10) (control group; HES0), 0.1% hesperidin group (HES1), and 0.2% hesperidin group (HES2)) with five replicates. It has been found in the analysis that hesperidin did not affect the weight and thickness of the shell from the external quality parameters of the egg (P > 0.05), but in terms of the HES1 and HES2 groups, the weight of the egg increased compared to the HES0 group, while the fracture resistance of the shell decreased (P < 0.05). Eggs' internal quality parameters have shown that the egg white width (P < 0.05) and the yolk diameter (P < 0.01) increased in the HES1 and HES2 groups, and the length of white decreased (P < 0.05). It has been found that n-6 (linoleic acid) and n-3 (docosahexaenoic acid) fatty acid values increased significantly according to hesperidin dosage (P < 0.05) from the parameters of the composition of fatty acids of the eggs. As a result, it is believed that hesperidin added to the diet has a generally positive effect on the fatty acid composition and internal and external quality parameters of the eggs and would be appropriate to use it as a feed additive.

Tea polyphenols increase the antioxidant status of laying hens fed diets with different levels of ageing corn

This study was conducted to evaluate the effects of ageing corn levels (stored for 4 years) with or without the supplementation of tea polyphenols (TPP) on the performance, egg quality and antioxidant status of laying hens. A total of 288 Lohmann commercial laying hens (63-week-old) were used under a 2 × 4 factorial arrangement with 4 levels of dietary ageing corn (0%, 25%, 50%, or 100%) and 2 levels of TPP (0 and 600 mg/kg) for 8 wk. Dietary ageing corn linearly decreased (P < 0.05) the egg production, serum total antioxidant capacity (T-AOC), liver glutathione peroxidase (GSH-Px) of laying hens, yolk index, yolk colour, 1,1-diphenyl-2-picrylhydrazyl (DPPH) value and the reducing power value of egg yolk, but it linearly increased (P < 0.05) the feed conversion rate, ovary malondialdehyde (MDA) content of laying hens, and the protein carbonyl content of egg yolk. Tea polyphenol supplementation increased (P < 0.05) the serum T-AOC, serum superoxide dismutase (SOD), liver SOD, liver GSH-Px, ovary SOD, GSH-Px, the expression of antioxidant-related genes of laying hens, albumen height, Haugh unit, DPPH value and the majority free amino acids of egg yolk, but it decreased (P < 0.05) the serum MDA content of laying hens, MDA and protein carbonyl of egg yolk. In conclusion, the ageing corn significantly reduced the performance, egg quality, antioxidant status and egg antioxidant capacity of laying hens, while TPP supplementation partially counteracted the adverse effects, especially antioxidant status and egg antioxidant capacity of laying hens.

Content and Composition of Phospholipids, Fatty Acids and Sterols in Commercial Natural Phospholipid Excipients

Background:

Phospholipids are widely used in food and pharmaceutical industry as functional excipients. In spite of the many analytical methods reported, there are very limited reports concerning systematic research and comparison of phospholipid excipients.

Objective:

To present a comprehensive evaluation of commercial natural phospholipid excipients (CNPEs).

Methods:

Seventeen batches of CNPEs from five manufacturing enterprises, isolated either from soybean or egg yolk, were investigated. The content and composition of phospholipids, fatty acids and sterols as a whole were considered as the evaluative index of CNPEs. Eight kinds of phospholipids were determined by Supercritical Fluid Chromatography (SFC), twenty-one kinds of fatty acids were determined by Gas Chromatography (GC) after boron trifluoride-methanol derivatization, and nine kinds of sterols were determined by High Performance Liquid Chromatography (HPLC) after separation and derivatization of the unsaponifiable matter. Cluster analysis was employed for the classification and identification of the CNPEs.

Results:

The results showed that each kind of CNPEs had its characteristic content and composition of phospholipids, fatty acids and sterols. Seventeen batches of samples were divided into eight groups in cluster analysis. CNPEs of the same type from different source (soybean or egg yolk) or enterprises presented different content and composition of phospholipids, fatty acids and sterols.

Conclusion:

Each type of CNPEs had its characteristic content and composition of phospholipid, fatty acid and sterol. The compositions of phospholipid, fatty acid and sterol as a whole can be applied as an indicator of the quality and characteristics for CNPEs.

Effects of supplementation of dietary humate, probiotic, and their combination on performance, egg quality, and yolk fatty acid composition of laying hens

This study was carried out to determine the effects of addition of humate, probiotic, and their combination into diets on performance, egg quality, and yolk fatty acid composition of hens during the second laying period. Lohmann LSL white layers (n = 192), 46 weeks of age, were randomly divided into 4 groups and fed with basal diet (control, C), 0.3% humate (H), 0.3% probiotic (P), 0.15% humate + 0.15% probiotic (HP) for 18 weeks. Feed consumption and egg production were determined daily, egg weight was measured biweekly, and body weights were recorded at the beginning and the end of the experiment. Also, 12 egg samples from each group were randomly collected to determine the egg quality every 30 days. Laying performance, yolk color, and fatty acid composition were significantly (P < 0.05 and P < 0.01) affected by addition of humate, probiotic, and their combination into diets of layers. The HP group had higher cracked egg yield and feed conversion ratio values than control and H and P groups. Except for egg yolk color, the other egg quality parameters such as shape index, shell strength, shell thickness, albumen index, yolk index, and Haught unit were not affected by treatment (P < 0.05 and P < 0.01). The egg yolks of treatment groups had less stearic acid than those of control group. In conclusion, supplementation of humate and probiotic into the diets of laying hens increased monounsaturated fatty acids in yolk and improved feed conversion ratio and egg yolk color.

Effect of supplementation with solid-state fermented feed in the diet of laying hens on egg qualitative variables

   The aim of this experiment was to evaluate the effect of the supplementation of laying hens diet with solid-state fermented feed on egg qualitative variables. The diet of laying hens was supplemented with 10% and 15% of solid-state feed fermented by the low filamentous fungal strain Mortierella alpina CCF 2861. For the trial, 30 Lohmann Brown classic layers, aged 17 weeks, were selected and individually weighed and divided into three groups (control and two experimental groups). The control group of laying hens was fed with basic feed mixture and the experimental groups received the same diet as a control group, but enriched with supplementation of solid-state fermented feed. The first experimental group was fed a diet supplemented with 10% of fermented feed and the second experimental group with 15% supplementation. The following egg qualitative variables were observed: the egg weight, Haugh units, quality grade, air cell depth, percentage of the shell, yolk and albumen, eggshell breaking force, pH of egg yolk and albumen, egg yolk colour, and antioxidant activity with the extent of lipid oxidation in egg yolk samples. The pH of yolk and albumen did not show differences between all examined eggs originating from the experimental groups of laying hens (p >0.05). The eggs from both experimental groups had a significantly higher eggshell hardness than eggs produced by the hens of the control group (p <0.05). Antioxidant activity of egg yolk of experimental samples increased with the supplementation of fermented feed in the diet of laying hens (p <0.05). The specific lightness of egg yolk colour increased significantly in the experimental group with 15% of supplementation (p <0.01). The obtained results showed that feeding laying hens with fermented feed positively affected the quality of produced eggs. This was the first study and further investigation before using the fermented feed in commercial laying hen farms is necessary.

The Effect of Dietary Humic Preparations on the Content of Essential and Non-Essential Chemical Elements in Hen Eggs

This study was conducted to determine the effect of dietary supplementation with two humic preparations, Humokarbowit (HKW) and Humobentofet (HBF), on the mineral content of the albumen and egg yolk of Lohmann Brown hens. The content of macroelements (Ca, K, Mg, Na, P, S), microelements (Al, Ba, Cu, Fe, I, Mn, Si, Sr, Zn) and trace elements (Ag, As, Be, Bi, Cd, Co, Cr, Ga, Hg, Li, Mo, Ni, Pb, Rb, Sb, Se, Sn, Ti, Tl, V, W, Y and Zr) in the feed mixture (FM), albumen and yolk were presented. The material was collected from laying hens kept in a cage system in two groups, control (C) and enriched (E), with standard feed and feed enriched with humic preparations, respectively. The enriched feed mixture was characterised by a significantly higher Ag, Ba, Be, Bi, Co, Fe, Ga, Hg, K, Mg, Ni, S, Sb, Si, Zn and Zr content compared to the standard, basal mixture. Only some of these elements were found in significantly increased levels in albumen (Bi, Co, Ni, S) and yolk (Bi, Fe, K, Sb). Another noteworthy finding was a significantly lower concentration of Na in the content of eggs from the E-Group, which corresponds to the content of this important macronutrient in the feed. In addition, a significant increase in the concentration of elements such as Al, I, Li, Sr, Ti, Tl, Y, W was noted with a reduction in Cd, Cr, Hg, Mn, Rb, Sn in Group-E, which indicates a complicated egg formation processes, including biotransfer-essential and non-essential chemical elements.

Valorization of Corn Seed Oil Acid Degumming Waste for Phospholipids Preparation by Phospholipase D-Mediated Processes

This work focused on the phospholipase D-mediated treatment of the waste residue coming from acid degumming, which constitutes the second part of the degumming step in the crude corn edible oil refining process. This industrial process produces a complex by-product (called gum), a mixture containing phospholipids (PLs) whose composition depends on the nature of the oil source. This residue is usually disposed of with the consequential costs and environmental concerns. An efficient multistep protocol of physical separations of the PL-rich fraction from waste gums has been set up, including centrifugation, precipitation and solvent partitioning. This waste stream, which is thoroughly characterized after the concentration process, constitutes a renewable feedstock for the production of value-added PLs with modified polar head-exploiting phospholipase D-mediated biotransformations, which have been successfully performed on this complex natural mixture. The valorization of these waste gums through the production of high value PLs for targeted applications paves the way to a new alternative approach for their disposal, which could be of great interest from a circular economy perspective.

Lipase Catalyzed Acidolysis for Efficient Synthesis of Phospholipids Enriched with Isomerically Pure cis-9,trans-11 and trans-10,cis-12 Conjugated Linoleic Acid

The production of phospholipid (PL) conjugates with biologically active compounds is nowadays an extensively employed approach. This type of phospholipids conjugates could improve bioavailability of many poorly absorbed active compounds such as isomers of conjugated linoleic acid (CLA), which exhibit versatile biological effects. The studies were carried out to elaborate an efficient enzymatic method for the synthesis of phospholipids with pure (>90%) cis-9,trans-11 and trans-10,cis-12 CLA isomers. For this purpose, three commercially available immobilized lipases were examined in respect to specificity towards CLA isomers in acidolysis of egg-yolk phosphatidylcholine (PC). Different incorporation rates were observed for the individual CLA isomers. Under optimal conditions: PC/CLA molar ratio 1:6; Rhizomucor miehei lipase loading 24% wt. based on substrates; heptane; DMF, 5% (v/v); water activity (aw), 0.11; 45 °C; magnetic stirring, 300 rpm; 48 h., effective incorporation (EINC) of CLA isomers into PC reached ca. 50%. The EINC of CLA isomers was elevated for 25–30% only by adding a water mimic (DMF) and reducing aw to 0.11 comparing to the reaction system performed at aw = 0.23. The developed method of phosphatidylcholine acidolysis is the first described in the literature dealing with isometrically pure CLA and allow to obtain very high effective incorporation.

NMR-based differentiation of conventionally from organically produced chicken eggs in Germany

Both the German and European organic food markets are growing fast, and there is also a rising demand for organic chicken eggs. Consumers are willing to pay higher prices for organic eggs produced in an animal-appropriate environment considering animal welfare. Strict labelling requirements do not prevent chicken eggs from being a subject of food fraud. Conventionally produced (barn/free-range) eggs can easily be mislabeled as organic eggs. Especially because the demand for organically produced chicken eggs is likely to exceed supply in the future, mislabeling appears to be a realistic scenario. Therefore, there is a need for analytical methods that are suitable to classify eggs as being either conventionally or organically produced. Nuclear magnetic resonance (NMR) spectroscopy in combination with multivariate data analysis is a suitable tool to screen eggs according to the different systems of husbandry. Sample preparation is based on a fat extraction method, which was optimised for application to freeze-dried egg yolk. Samples were analysed using typical q-NMR parameters. A nontargeted approach was used for the analysis of the ¹ H NMR data. Principal component analysis (PCA) was applied followed by a linear discriminant analysis (PCA-LDA) and Monte Carlo cross-validation. In total, 344 chicken eggs (214 barn/free-range eggs and 130 eggs from organic farms), most of them originating from Germany, were used to build and validate the prediction model. The results showed that the prediction model allowed for the correct classification of about 93% of the organic eggs.

Modeling of Dielectric and Thermal Properties of Protein-Enriched Instant Noodles as a Function of Food Chemical Composition

Dielectric property measurement instruments are expensive and not readily available. Hence, models of the dielectric and thermal properties of protein-enriched instant noodles (PEIN) were developed as a function of the product moisture, protein, ash, fat, carbohydrate, and crude fiber contents. The chicken meat, egg yolk, and seaweed in PEIN varied from 0 to 30, 0 to 15, and 0 to 6 g/100 g flour, respectively. Results revealed that protein, fat, and ash contents of PEIN increased by chicken meat, egg yolk, and seaweed supplementation. Regression equations indicated that the moisture and protein contents significantly (P ≤ 0.05) increased, while the fat content decreased the dielectric and thermal properties. The R2 values of the dielectric constant and loss factor, thermal conductivity, and specific heat equations were 0.75, 0.87, 0.78, and 0.98, respectively. Finally, no significant differences (P > 0.05) between the properties values predicted from the model equations and the experimental data (not included in the development of model equations) was observed which indicated a good model fit.

Dietary choline and phospholipid supplementation enhanced docosahexaenoic acid enrichment in egg yolk of laying hens fed a 2% Schizochytrium powder-added diet

The aim of this study was to evaluate the effect of dietary phospholipid supplementation on laying hen performance, egg quality, and the fatty acid profile of egg yolks from hens fed a 2% Schizochytrium powder diet. Three-hundred-sixty 28-wk-old Hy-line W-36 laying hens were randomly allocated to one of the 5 dietary treatments, each treatment with 6 replicates of 12 birds each. All diets included 2% Schizochytrium powder (docosahexaenoic acid [DHA], 137.09 mg/g). The control group was not supplemented with any additional phospholipids, whereas the other 4 experimental diets were supplemented with 1,000 mg/kg choline (CHO), 1,000 mg/kg monoethanolamine (MEA), 1,000 mg/kg lysophosphatidylcholine (LPC), or 500 mg/kg LPC + 500 mg/kg MEA (LPC + MEA). The experimental diets were isocaloric (metabolizable energy, 11.15 MJ/kg) and isonitrogenous (crude protein, 16.60%). The feeding trial lasted 28 days. Laying hen performance and egg quality were not affected (P > 0.05) by the diets used. The monounsaturated fatty acid (MUFA) level was reduced in the LPC group at d 28 (P < 0.01), whereas the polyunsaturated fatty acid (PUFA) level was increased (P < 0.05). The omega-6 (n-6) PUFA level of the egg yolks in the LPC group had a trend to increase in comparison to the control (P = 0.07). The CHO and LPC groups had higher omega-3 (n-3) PUFA and DHA levels and lower n-6/n-3 ratios than the other groups at d 28 (P < 0.01). The DHA content in egg yolk reached a plateau after the laying hens consumed the experimental diets for 14 days, and higher yolk DHA contents were observed in the CHO and LPC groups as compared with the other groups at d 14. It was concluded that dietary choline supplementation for more than 14 d enhanced egg yolk enrichment with n-3 PUFA and DHA when laying hen diets were supplemented with 2% Schizochytrium powder. All the diets had no adverse effect on hen performance, egg quality, or egg components under the experimental condition.

An RFID-Based Smart Nest Box: An Experimental Study of Laying Performance and Behavior of Individual Hens

This study designed a radio-frequency identification (RFID)-based Internet of Things (IoT) platform to create the core of a smart nest box. At the sensing level, we have deployed RFID-based sensors and egg detection sensors. A low-frequency RFID reader is installed in the bottom of the nest box and a foot ring RFID tag is worn on the leg of individual hens. The RFID-based sensors detect when a hen enters or exits the nest box. The egg-detection sensors are implemented with a resistance strain gauge pressure sensor, which weights the egg in the egg-collection tube. Thus, the smart nest box makes it possible to analyze the laying performance and behavior of individual hens. An evaluative experiment was performed using an enriched cage, a smart nest box, web camera, and monitoring console. The hens were allowed 14 days to become accustomed to the experimental environment before monitoring began. The proposed IoT platform makes it possible to analyze the egg yield of individual hens in real time, thereby enabling the replacement of hens with egg yield below a pre-defined level in order to meet the overall target egg yield rate. The results of this experiment demonstrate the efficacy of the proposed RFID-based smart nest box in monitoring the egg yield and laying behavior of individual hens.

Association Between Arachidonic Acid and Chicken Meat and Egg Flavor, and Their Genetic Regulation

In Japan, the majority of chicken meat is obtained from fast-growing broiler chickens. Because most Japanese chicken breeds have a low meat yield and egg production, many of these breeds are endangered. Recently, the palatability of meat and eggs of native chickens has been reevaluated in the Japanese market. Jidori, which means chicken from the local, is an indigenous local chicken that is more delicious, firmer in texture, and more expensive than the broiler chickens. Most Japanese consumers recognize that the meat of Jidori chicken is richer in flavor than that of the broiler chicken. However, the reason for this rich flavor of the meat of Jidori chicken has not been elucidated. Recently, we found that arachidonic acid (AA) (C20:4n-6), a polyunsaturated fatty acid, is associated with the rich flavor of the meat and eggs of Jidori chicken. The present paper summarizes the discovery of the involvement of AA in the flavor characteristic of the meat and eggs of chicken, and also the genetic regulation of the AA content in the meat and eggs of Jidori chicken.

Lipase-Catalyzed Transesterification of Egg-Yolk Phophatidylcholine with Concentrate of n-3 Polyunsaturated Fatty Acids from Cod Liver Oil

Phospholipids containing PUFAs are important vehicles for their delivering to the targeted tissues. In our research project we established enzymatic methods for the enrichment of natural egg-yolk PC with n-3 PUFAs. Instead of synthetic PUFA ethyl esters, the new strategy was developed using polyunsaturated fatty acids enriched fraction (PUFA-EF) from cod liver oil as the natural acyl donors. PUFA-EF was produced by urea-complexation and contained 86.9% PUFA including 8.5% stearidonic acid (SDA; 18:4(n-3)), 26.7% EPA, and 45.2% DHA. The transesterification of PC with PUFA was catalyzed by lipases. After screening of enzymes the effect of reaction medium; molar ratio of substrates and etc. was investigated. The highest incorporation of PUFA was 45.6%; including 36.8% DHA and 5.8% EPA at the following reaction conditions: hexane; 55 °C; PUFA-EF/PC acyl ratio of 10; 48 h of reaction time and lipase B from Candida antarctica as a biocatalyst (20% of enzyme load).

Effect of humates in diet of dairy cows on the raw milk main components

The effect of supplemental humic substances (HS) on the main milk components was investigated. A total of 10 dairy cows (Czech pied cattle, crossbred Czech pied cattle ´ Ayrshire and crossbred Czech pied cattle ´ Red Holstein) were tested. Animals were randomly divided into 2 groups, control (C) and experimental (E). Animals fed the same feed mixture and group E was additionally supplemented with HS (200 mg.kg-1 of product Humafit prepared from the Sakhalin Leonardite). The experimental period took 3 months. Cows were milked twice a day. The milk composition (lactose, fat, crude protein, pure protein and casein) of every cow was monitored on days 0, 14, 28, 42, 56, 70 and 84 of the experiment. Pure protein content was determined by Kjeldahl method, other components were analysed using an infrared analyserMilkoScan FT 120. It was found that the crude protein, pure protein and casein content in milk of group E significantly (p <0.05) increased from the 56th day of the experimental period. Differences of the protein fraction contents in group C and of the dry matter, non-fat dry matter, lactose and fat content in both groups were non-significant (p <0.05).Higher protein and especially casein content in milk could be very important for the cheesemaking as it could increase the cheese yield.

Increasing Levels of Dietary Hempseed Products Leads to Differential Responses in the Fatty Acid Profiles of Egg Yolk, Liver and Plasma of Laying Hens

The limited efficiency with which dietary alpha-linolenic acid (ALA) is converted by hens into docosahexaenoic acid (DHA) for egg deposition is not clearly understood. In this study, dietary ALA levels were increased via the inclusion of hempseed (HS) and hempseed oil (HO) in hen diets, with the goal of assessing the effects on the fatty acid (FA) profiles of total lipids and lipid classes in yolk, liver and plasma. Forty-eight hens were individually caged and fed one of six diets containing either HS:10, 20 or 30, HO:4.5 or 9.0 (%, diet) or a control (containing corn oil), providing a range (0.1-1.28 %, diet) of ALA. Fatty acid methyl esters of total lipids and lipid classes, including phosphatidyl choline (PtdCho) and ethanolamine (PtdEtn) in yolk, plasma and liver were then determined. Levels of n-3 FAs in both total lipids and lipid classes increased in all tissues. ALA and eicosapentaenoic acid (EPA) increased linearly, while docosapentaenoic acid and DHA increased quadratically. The FA profiles of yolk closely reflected levels in both plasma and liver. While ALA was highly concentrated in the triacylglycerol, it was low but equally distributed between PtdCho and PtdEtn in all tissues; however, the net accumulation was lower (P < 0.0001) in liver compared to yolk and plasma. Levels of EPA and ALA in yolk-PtdEtn were linearly (P < 0.0001; R (2) = 0.93) associated, and reflected those in liver-PtdEtn (P < 0.0001; R (2) = 0.90). In the liver, a strong inverse correlation (P < 0.0001; r = -0.94) between PL-DHA and ALA-to-EPA ratio in PtdEtn supports theories of low substrate availability, possibly limiting the conversion of ALA into DHA for egg enrichment.

Determination of total antioxidant capacity of humic acids using CUPRAC, Folin-Ciocalteu, noble metal nanoparticle- and solid-liquid extraction-based methods

Total antioxidant capacity (TAC) of humic acid (HA) samples was determined using CUPRAC (CUPric Reducing Antioxidant Capacity), FC (Folin-Ciocalteu), QUENCHER-CUPRAC, QUENCHER-FC, Ag-NP (Silver nanoparticle)‒ and Au-NP (Gold nanoparticle)‒based methods. Conventional FC and modified FC (MFC) methods were applied to solid samples. Because of decreased solubility of Folin-Ciocalteu's phenol reagent in organic solvents, solvent effect on TAC measurement was investigated using QUENCHER-CUPRAC assay by using ethanol:distilled water and dimethyl sulfoxide:distilled water with varying ratios. To see the combined effect of solubilization (leaching) and TAC measurement of humic acids simultaneously, QUENCHER experiments were performed at 25°C and 50°C; QUENCHER-CUPRAC and QUENCHER-FC methods agreed well and had similar precision in F-statistics. Although the Gibbs free energy change (ΔG°) of the oxidation of HA dihydroxy phenols with the test reagents were negative, the ΔG° was positive only for the reaction of CUPRAC reagent with isolated monohydric phenols, showing CUPRAC selectivity toward polyphenolic antioxidants. This is the first work on the antioxidant capacity measurement of HA having a sparingly soluble matrix where enhanced solubilization of bound phenolics is achieved with coupled oxidation by TAC reagents.

Phospholipids in foods: prooxidants or antioxidants?

Lipid oxidation is one of the major causes of quality deterioration in natural and processed foods and thus a large economic concern in the food industry. Phospholipids, especially lecithins, are already widely used as natural emulsifiers and have been gaining increasing interest as natural antioxidants to control lipid oxidation. This review summarizes the fatty acid composition and content of phospholipids naturally occurring in several foods. The role of phospholipids as substrates for lipid oxidation is discussed, with a focus on meats and dairy products. Prooxidant and antioxidant mechanisms of phospholipids are also discussed to get a better understanding of the possible opportunities for using phospholipids as food antioxidants.

The Effect of Humic-Fatty Acid Preparation on Production Parameters and Meat Quality of Growing Rabbits

The aim of the study was to determine the effect of a humic-fatty acid preparation on production parameters and meat quality of rabbits. Three groups of New Zealand White rabbits were used (one control and two experimental) with 8 animals per group. The animals of group C (control) were fed standard pelleted diet, group H5 received a control diet supplemented with 5%, and group H10 a control diet with 10% humic-fatty acid preparation. The experiment was terminated after 6 weeks feeding, when rabbits were slaughtered. The experimental groups showed higher gains and a higher feed conversion ratio than the control group. The dietary inclusion of the experimental additive had a beneficial effect on the meat quality traits, such as Fe concentration, hardness and colour, but it also increased the susceptibility of fat to oxidative changes.