Review: Nutritional aspects of hemp-based products and their effects on health and performance of monogastric animals

Sustainable agriculture aims to produce food and feed that ensure food security and play a key role in environmental protection. For this, producers, supported by scientific research, are investigating new protein alternatives for animals that guarantee high performance and preserve their health. Among these, hemp (Cannabis sativa L.) is gaining great success, both for its active role in environmental conservation and for the high nutritional profile of the seeds (20-30% carbohydrates, 25-30% proteins easy to digest and rich in essential amino acids, and 25-35% lipids with a balanced fatty acid composition), also ensured by the co-products, particularly seed cakes (30-34% proteins and 10-12% lipids). However, the last scientific report by the European Food Safety Authority for the use of hemp-based products in the feed sector now dates back to 2011. For this reason, the objective of this review, in addition to outlining the nutritional profile of hempseeds (HSs) and co-products, aims to investigate their use in the monogastric sector, particularly in the diets of pigs, broilers, and laying hens, by summarising the main works in the literature up to 2023, investigating the effects on animal health and performances. The reported results showed that the addition of 50 g/kg of HSs and HS oil improved the nutritional profile of milk and colostrum in lactating sows, particularly the lipid profile, positively affecting the health of piglets. For broilers, the inclusion of HSs (20 g/kg) resulted in better values on growth performance. This was not matched by the addition of HS oil (up to 60 g/kg). In particular, although a better polyunsaturated fatty acid profile was observed, the results on growth performance were contradictory. The same trend was observed for HSs cakes with 50, 150, and 200 g/kg inclusion. For laying hens, the inclusion of HSs (up to 250 g/kg), HS oil (up to 300 g/kg), and HSs cake (up to 150 g/kg) increased the nutritional and functional profile of the eggs, safeguarding performance and animal welfare. However, despite the promising results, the function of hemp-based products in the diet of monogastric animals needs to be further investigated to identify the optimal level of inclusion and timing of administration, necessary to ensure high performance and health of the animals.

Value-added green biorefinery co-products from ultrasonically assisted DES-pretreated Chlorella biomass

This study pursued the goal of creating value-added co-products through an environmentally friendly biorefinery approach, employing ultrasonically assisted deep eutectic solvent (DES)-pretreated Chlorella biomass. The primary focus was on generating enriched biodiesel feedstock with exceptional fuel properties and developing hydroponic biofertilizer. The results demonstrated the effectiveness of a two-step process involving a 5-minute ultrasound-assisted DES pretreatment followed by ultrasound-assisted solvent extraction, which efficiently extracted lipids from Chlorella biomass, yielding biodiesel-quality lipids with good cetane number (59.42) and high heating value (40.11 MJ/kg). Notably, this two-step approach (78.04 mg-lipid/g-microalgal biomass) led to a significant 2.10-fold increase in lipid extraction compared to a one-step process (37.15 mg-lipid/g-microalgal biomass) that combined ultrasound-assisted DES pretreatment and solvent extraction. Importantly, the aqueous extract derived from lipid-extracted microalgal biomass residues (LMBRs) showed promise as a component in hydroponic biofertilizer production, supporting lettuce growth in hydroponic deep water culture system. Consequently, microalgae biorefinery co-products hold tremendous potential in enhancing the profitability and sustainability of interconnected sectors, encompassing renewable energy, agriculture, and the environment.

Safety assessment of fish oil green extraction and in vivo acute toxicity evaluation

Sardine co-products can represent an interesting source of bioactive compounds, such as polyunsaturated fatty acids and in particular omega-3. This study aimed to investigate extraction of oil from sardine co-products by enzymatic hydrolysis using two proteases: commercial Alcalase and protease Bb from a local fungal strain (P2) of Beauveria bassiana, which overproduces proteases. Despite a higher degree of hydrolysis (41.34%) than Alcalase (24.28%), protease Bb allowed the extraction of approximately the same oil content. Resulting oil from both processes had the same fatty acid profile. Interestingly, the all-produced oil displayed an attractive w6/w3 ratio, an indicator of nutritional quality, of the order of 0.16. The safety of the generated oils was also assessed by treating two groups of Wistar rats with the fish oil administered by oral gavage at the doses (30 mg/kg and 300 mg/kg body weight) for 14 days using olive oil as a vehicle. Compared to controls used, both treated groups showed no statistically significant differences. Consequently, the acute oral toxicity evaluated by hematological, biochemical, and histological studies showed the safety of the oil generated using B. bassiana protease.

Effect of recovery technique, antioxidant addition and compositional features on lipid oxidation in protein enriched products from cod- salmon and herring backbones

The influence of recovery technique (pH-shift processing vs mechanical separation), antioxidant addition and endogenous factors on lipid oxidation in protein-enriched products from herring, salmon and cod backbones was investigated. Salmon-derived products were very stable during both ice and -20 °C storage. Contrary, peroxide value and TBA-reactive substances in herring- and cod-derived products increased rapidly during ice storage, with the pH-shift-produced protein isolates (PI) being most susceptible to oxidation in case of cod. Duralox MANC (0.5%) however largely increased the oxidation lag phase in both PI and mechanically separated meat (MSM); from <1 day to >15 days. At -20 °C, mainly the herring products oxidized, and particularly the MSM. Pearson correlation tests showed that endogenous levels of Hb, total Fe, ascorbic acid and α-tocopherol correlated significantly (p < 0.05) with lipid oxidation development. Evaluating the role of pre-processing storage indicated that fish co-products should be processed immediately after the filleting process unless antioxidants are added.

Feeding behavior of feedlot lambs fed diets with different energy and protein sources

This study aimed to evaluate the effect of the replacement of ground corn by crude glycerin and soybean meal by cottonseed cake, in association or not, on feedlot lambs' feeding behavior. Thirty-two non-castrated crossbred ½ Dorper ½ Santa Inês lambs, with an average body weight of 18.52 ± 3.24 kg (mean ± standard deviation), were distributed in a completely randomized design, into four treatments and eight replicates per treatment, in a 2 × 2 factorial scheme. Four experimental diets were tested with different sources or combinations of energy and protein ingredients in the concentrate, respectively: (1) ground corn + soybean meal; (2) ground corn and cottonseed cake; (3) crude glycerin and soybean meal; and (4) crude glycerin and cottonseed cake. The glycerin decreased dry matter (DM) and neutral detergent fiber (NDF) (P < 0.001) intakes, whereas it increased times spent in feeding (P = 0.009; from 21.8 to 28.6), rumination (P = 0.006; from 56.2 to 67.2), and chewing (P < 0.001; from 79.4 to 97.2), in minutes/100 g of DM. Feeding efficiencies of DM (P = 0.003) and NDF (P = 0.008) were decreased by the diets. Protein sources increased (P = 0.018) the times spent in chewing and per period in rumination (P = 0.014). Cottonseed cake, as a protein source, up to a 112 g/kg DM level, can totally replace soybean meal in diets for feedlot lambs without effects on the intake, behavioral activities, and feeding efficiencies. In contrast, the crude glycerin energy source is not adequate to replace ground corn in lambs' diets.

Biofuels Co-Products Tolerance and Toxicology for Ruminants: An Update

Corn co-products are a co-product of the dry and wet corn-milling ethanol manufacturing industry. The dry mill corn co-product is distiller's grains. Distillers grain can be further categorized into dry distillers grains (DDG), DDG with solubles, wet distillers grains with solubles (WDGS), modified WDGS, and corn syrup (solubles). Wet mill ethanol production produces 2 main feed stuffs: corn gluten (wet and dry) and heavy steep water.

Quantification of zearalenone and α-zearalenol in swine liver and reproductive tissues using GC-MS

The mycotoxin zearalenone (ZEN) is a common contaminant of swine feed which has been related to a wide range of reproductive anomalies in swine, such as pelvic organ prolapse, anestrous, and pseudopregnancy. New information is needed to understand how ZEN and related metabolites accumulate in swine reproductive tissues. We conducted a feeding study to track ZEN and the metabolite α-zearalenol (α-ZEL) in swine liver and reproductive tissues. Thirty pubertal gilts were randomly assigned one of three treatments, with ten pigs in each treatment group: (1) base feed with solvent for 21 days, (2) ZEN-spiked feed for seven days followed by base feed with solvent for 14 days, and (3) ZEN-spiked feed for 21 days. At the end of the trial, liver, anterior vagina, posterior vagina, cervix, uterus, ovaries, and broad ligament were collected from pigs. ZEN was found in the anterior vagina, posterior vagina, cervix, and ovaries, with significantly higher concentrations in the cervix relative to other reproductive tissues. ZEN and α-ZEL were found in liver tissue from pigs in each treatment group. Our results show that ZEN accumulates more in the cervix than other reproductive tissues. The presence of ZEN in reproductive tissues may be indicative of ZEN-related reproductive symptoms. Future work could examine how ZEN concentrations vary in reproductive tissues as a factor of the pigs age, weight, sex, or parity, to establish parameters that make pig more sensitive to ZEN.

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A feeding trial was conducted where gilts consumed varying amounts of zearalenone.

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Zearalenone was found in the anterior vagina, posterior vagina, cervix, and ovaries.

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Zearalenone concentrations were highest in the cervix.

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Zearalenone and alpha-zearalenol were found in the liver.

Extraction of proteins from the microalga Scenedesmus obliquus BR003 followed by lipid extraction of the wet deproteinized biomass using hexane and ethyl acetate

A current problem of the lipid extraction from wet biomass is the formation of emulsions during the mixing of the microalgal biomass and organic solvents. It has been suggested that microalgal proteins play an important role in the formation and stability of such emulsions. Herein, the extraction of proteins of the freshwater microalga Scenedesmus obliquus BR003 was optimized for further extraction of lipids from the wet deproteinized biomass. The optimal (pH 12 at 60 °C for 3 h) and moderate (pH 10.5 at 50 °C for 2 h) conditions of protein extraction resulted in protein yields of 20.6% and 15.4%, respectively. Wet lipid extraction of deproteinized biomass resulted in a less stable emulsion that released twice the solvent than the control biomass. However, the faster separation of phases that occurred during the wet lipid extraction of the deproteinized biomass resulted in a lipid yield twice lower than the control biomass.

Standardized ileal digestibility of amino acids in cereal grains and co-products in growing pigs

Objective

The objective was to determine standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in cereal grains and various co-products fed to growing pigs.

Methods

Ten feed ingredients tested were barley (9.3% CP), lupin kernels (31.1% CP), and wheat (11.3% CP) as cereal grains, and 2 sources of corn gluten feed produced in China (21.6% CP) and Korea (24.6% CP), corn gluten meal (65.3% CP), lupin hulls (11.6% CP), rice bran (14.5% CP), soybean meal (44.8% CP), and wheat bran (15.4% CP) as co-products. Ten experimental diets were formulated to contain each ingredient as a sole source of N and an N-free diet was used to correct basal endogenous losses of CP and AA. All diets also contained 0.5% Cr₂O₃ as an indigestible index. A replicated 11×6 incomplete Latin square design with 11 dietary treatments, 6 periods, and 22 animals was employed. Twenty-two barrows with an initial body weight of 64.6±4.9 kg were equipped with a T-cannula in the distal ileum. An experimental period consisted of a 4-d adaptation period and a 2-d collection period.

Results

The SID of CP in the barley, lupin kernels, wheat, 2 sources of corn gluten feed, corn gluten meal, lupin hulls, rice bran, soybean meal, and wheat bran were 84.7%, 90.5%, 90.4%, 77.4%, 74.6%, 89.5%, 90.4%, 74.4%, 86.9%, and 63.4% (standard error of the mean [SEM] = 5.3, p = 0.006), respectively. The respective SID values of Lys were 75.5%, 88.4%, 83.9%, 74.7%, 62.4%, 80.3%, 83.9%, 78.5%, 88.0%, and 71.2% (SEM = 3.3, p<0.001), and the SID values of Met were 83.6%, 88.7%, 89.4%, 85.7%, 78.3%, 88.9%, 89.4%, 85.3%, 91.1%, and 77.0% (SEM = 2.4, p<0.001), respectively.

Conclusion

The ileal digestibility of protein and amino acids varies among the feed ingredients fed to pigs.

In Vitro Anticoccidial Activity of Olive Pulp (Olea europaea L. var. Chemlal) Extract Against Eimeria Oocysts in Broiler Chickens

AIM

The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally.

MATERIALS AND METHODS

The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography-mass spectrometry with electrospray ionisation (HPLC-ESI-MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm.

RESULTS

Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R² = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity.

CONCLUSION

To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens.

Estimation of daily nutrient allowances for pigs fed with alternative feed resources in smallholder enterprises in Kenya

This study estimated the daily nutrient allowances from conventional commercially compounded feed and alternative feeds resources in smallholder pig enterprises in Busia, Nakuru, and Kiambu counties in Kenya. Feeding data from 144 pig enterprises was used to compute the daily dry matter (DM), crude protein (CP), and metabolisable energy (ME) supplied to pigs per kilogram bodyweight. Analysis of variance of the mean values was computed using SPSS statistical software and SAS® systems with Tukey's test to separate the means. Results showed that the daily nutrient allowance provided by some alternative feed resources was generally very low; however, home-made feed formulations supplied reasonably sufficient dietary energy and CP. Swill was the most popular feed resource in Busia County; however, the amount of energy supplied from swill was very low (ME = 19.98 kcal/kg body weight). The daily CP allowance for pigs fed on swill, farm residue, and market waste was very low ranging between 1.1 and 3.6 g/kg body weight. The findings of this study indicate that there is need for capacity development for farmers with respect to feeding practices that have no capacity to supply sufficient nutrient allowances. Research should focus more improving supply of nutrients from viable alternative feed resources through use of technology.

Cultivation of an algae-bacteria consortium in wastewater from an industrial park: Effect of environmental stress and nutrient deficiency on lipid production

Adoption of microalgae-sourced products depends on the economic feasibility. In the case of fatty acids, it is crucial to obtain high lipid yield, especially in the form of storage lipids (TAGs). However, the production of these lipids often comes into competition with the microalgae biomass, resulting in a decrease in growth. A microalgae culture integration project was conducted in an industrial park in Canada in order to cultivate microalgae from park's wastewaters and then obtain products from the biomass. Different deficiencies and stresses were tested to evaluate what condition allowed the induction of the highest lipids accumulation without compromising the growth of microalgae. The results showed that the medium controlled to pH 7.0 allowed reaching the largest amount of extracted lipids (28 ± 4.3%). Companies involved in this project could be able to make significant savings by the reduced wastewater treatment costs and by not adding expensive nutrients in culture.

Atlantic salmon (Salmo salar) co-product-derived protein hydrolysates: A source of antidiabetic peptides

Large quantities of low-value protein rich co-products, such as salmon skin and trimmings, are generated annually. These co-products can be upgraded to high-value functional ingredients. The aim of this study was to assess the antidiabetic potential of salmon skin gelatin and trimmings-derived protein hydrolysates in vitro. The gelatin hydrolysate generated with Alcalase 2.4L and Flavourzyme 500L exhibited significantly higher (p < 0.001) insulin and GLP-1 secretory activity from pancreatic BRIN-BD11 and enteroendocrine GLUTag cells, respectively, when tested at 2.5 mg/mL compared to hydrolysates generated with Alcalase 2.4L or Promod 144MG. The gelatin hydrolysate generated with Alcalase 2.4L and Flavourzyme 500L showed significantly more potent (p < 0.01) DPP-IV inhibitory activity than those generated with Alcalase 2.4L or Promod 144MG. No significant difference was observed in the insulinotropic activity mediated by any of the trimmings-derived hydrolysates when tested at 2.5 mg/mL. However, the trimmings hydrolysate generated with Alcalase 2.4L and Flavourzyme 500L exhibited significantly higher DPP-IV inhibitory (p < 0.05:Alcalase 2.4L and p < 0.01:Promod 144MG) and GLP-1 (p < 0.001, 2.5 mg/mL) secretory activity than those generated with Alcalase 2.4L or Promod 144MG. The salmon trimmings hydrolysate generated with Alcalase 2.4L and Flavourzyme 500L when subjected to simulated gastrointestinal digestion (SGID) was shown to retain its GLP-1 secretory and DPP-IV inhibitory activities, in addition to improving its insulin secretory activity. However, the gelatin hydrolysate generated with Alcalase 2.4L and Flavourzyme 500L was shown to lose GLP-1 secretory activity following SGID. A significant increase in membrane potential (p < 0.001) and intracellular calcium (p < 0.001) by both co-product hydrolysates generated with Alcalase 2.4L and Flavourzyme 500L suggest that both hydrolysates mediate their insulinotropic activity through the K_ATP channel-dependent pathway. Additionally, by stimulating a significant increase in intracellular cAMP release (p < 0.05) it is likely that the trimmings-derived hydrolysate may also mediate insulin secretion through the protein kinase A pathway. The results presented herein demonstrate that salmon co-product hydrolysates exhibit promising in vitro antidiabetic activity.

Evaluation of allocation methods for calculation of carbon footprint of grass-based dairy production

A major methodological issue for life cycle assessment, commonly used to quantify greenhouse gas emissions from livestock systems, is allocation from multifunctional processes. When a process produces more than one output, the environmental burden has to be assigned between the outputs, such as milk and meat from a dairy cow. In the absence of an objective function for choosing an allocation method, a decision must be made considering a range of factors, one of which is the availability and quality of necessary data. The objective of this study was to evaluate allocation methods to calculate the climate change impact of the economically average (€/ha) dairy farm in Ireland considering both milk and meat outputs, focusing specifically on the pedigree of the available data for each method. The methods were: economic, energy, protein, emergy, mass of liveweight, mass of carcass weight and physical causality. The data quality for each method was expressed using a pedigree score based on reliability of the source, completeness, temporal applicability, geographical alignment and technological appropriateness. Scenario analysis was used to compare the normalised impact per functional unit (FU) from the different allocation methods, between the best and worst third of farms (in economic terms, €/ha) in the national farm survey. For the average farm, the allocation factors for milk ranged from 75% (physical causality) to 89% (mass of carcass weight), which in turn resulted in an impact per FU, from 1.04 to 1.22 kg CO₂-eq/kg (fat and protein corrected milk). Pedigree scores ranged from 6.0 to 17.1 with protein and economic allocation having the best pedigree. It was concluded that when making the choice of allocation method, the quality of the data available (pedigree) should be given greater emphasis during the decision making process because the effect of allocation on the results. A range of allocation methods could be deployed to understand the uncertainty associated with the decision.

Prospects for commercial production of diatoms

In this review, a simple procedure that portends the open-pond growth of commercially viable diatoms is discussed. We examined a number of topics relevant to the production and harvesting of diatoms as well as topics concerning the production of bioproducts from diatoms. Among the former topics, we show that it is currently possible to continuously grow diatoms and control the presence of invasive species without chemical toxins at an average annual yield of 132 MT dry diatoms ha^-1 over a period of almost 5 years, while maintaining the dominancy of the optimal diatom species on a seasonal basis. The dominant species varies during the year. The production of microalgae is essentially agriculture, but without the ability to control invasive species in the absence of herbicides and insecticides, pollution and production costs would be prohibitive. Among the latter topics are the discussions of whether it is better to produce lipids and then convert them to biofuels or maximize the production of diatom biomass and then convert it to biocrude products using, for example, hydrothermal processes. It is becoming increasingly evident that without massive public support, the commercial production of microalgal biofuels alone will remain elusive. While economically competitive production of biofuels from diatoms will be difficult, when priority is given to multiple high-value products, including wastewater treatment, and when biofuels are considered co-products in a systems approach to commercial production of diatoms, an economically competitive process will become more likely.

Valorization of solid wastes from chestnut industry processing: Extraction and optimization of polyphenols, tannins and ellagitannins and its potential for adhesives, cosmetic and pharmaceutical industry

The aim of the current study was to evaluate the potential of chestnut peels to produce pomaces enhanced with tannins to be used in the formulations of wood adhesives, leather tanning or as natural antioxidants in food, cosmetic and pharmaceutical industry. An analytical procedure was planned as 2 factorial design to analyze the influence of solvent (water, Na2SO3 and NaOH at different concentrations of 1, 2, 4, and 8% in water) and extraction time (30, 60, and 120, 240, 480 and 960min) on extraction yield, pH, Stiasny index, and tannins. HPLC-diode array detector equipped with an ionization mass spectrophotometer was used to assess the polyphenol composition. Our results showed that both extraction properties and phytochemicals were significantly affected (P<0.001) by all independent factors. The main tannins identified were the hydrolyzable gallic acid, vescalagin castalagin and ellagic acid, and the condensed epigallocatechin, catechin and epicatechin. The solvent 1% Na2SO3 was more effective to extract the condensed tannins whilst hydrolyzable tannins were extracted efficiently by 1% NaOH. The multivariable analysis and the Pearson's correlation coefficients showed a direct association between Stiasny number and the average levels of condensed tannins.

The consequences of introducing stochasticity in nutrient utilisation models: the case of phosphorus utilisation by pigs

Simulation models of nutrient utilisation ignore that variation in pig system components can influence the predicted mean and variance of the performance of a group of pigs. The objective of this study was to develop a methodology to investigate how variation in feed composition would (a) affect the outputs of a nutrient utilisation model and (b) interact with variation that arises from the traits of individual pigs. We used a P intake and utilisation model to address these characteristics. Introduction of stochasticity gave rise to a number of methodological challenges--for example, how to generate variation in both feed composition and pigs and account for correlations between ingredients when modelling variation associated with feed mixing efficiency. Introducing variation in feed composition and pig phenotype resulted in moderate decreases in mean digested, retained and excreted P predicted for a population of pigs and an increase in their associated CV. A lower percentage of pigs in the population were predicted to meet their requirements during the feeding period considered, by comparison with the no-variation scenario. Variation in feed ingredient composition contributed more to performance variation than variation due to mixing efficiency. When variations in both feed composition and pig traits were considered, it was the former rather than the latter that had the dominant influence on variability in pig performance. The developed framework emphasises the consequences of random variability on the predictions of nutrient utilisation models. Such consequences will have a significant impact on decisions about management strategies such as feeding that are subject to variation.

Forest biorefinery: Potential of poplar phytochemicals as value-added co-products

The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species.

Valorization of pomegranate peel from 12 cultivars: dietary fibre composition, antioxidant capacity and functional properties

The dried powdered fruit peels of pomegranate (Punica granatum L.) (PomP) from 12 cultivars were used to extract and characterise their dietary fibre (DF) and to assess their functional and antioxidant properties. The total DF content varied between 33.10 and 62/100 g. The cellulose, Klason lignin, uronic acid and total neutral sugars (NS) composition of DF was: 16.53-22.71, 20.59-41.86, 13.98-23.31 and 16.88-19.66/100g, respectively. Arabinose and xylose were the most present NS with more than 60% of total NS content. The ratio of insoluble to soluble DF was around 1, reflecting the balanced composition of PomP's DF. Besides, PomP powder showed intermediate values for water- and oil-holding capacities: 2.31-3.53 and 2.80-4.05 mL/g, respectively, and strong retardation effect on the dialysis of glucose, reaching ∼60%. Also, it has been shown that most of the antioxidants can be extracted, based on the strong soluble antioxidant activity (2018-2649 μmol Trolox/g) compared to the insoluble one (13-23 μmol Trolox/g).

Phytochemicals in date co-products and their antioxidant activity

The date agro-industry needs to find appropriate techniques to give value to their co-products. This study analyzes twelve intermediate food products (IFPs) from date co-products, Medjool and Confitera cv. at several ripening stages, blanched and unblanched, for their content in bioactive compounds (phenols, tannins, flavonoids, carotenoids and anthocyanins) and the antioxidant activity (AA). IFPs from the more unripe stages had the highest AA and phytochemicals content, mainly phenols, up to 1.4 g GAE/100 g, with high proportions of tannins. Flavonoids were found in high amounts, up to 874 mg RE/100 g. Among the AA are significant the antiradical efficiency (4.62 mM TE/100 g) and chelating activity (252 μM EDTA/100 g). Blanching was beneficial for Confitera IFPs. A positive correlation was found between phenols, tannins and flavonoids and the AA; and their content could be used as indicator of the AA. Date IFPs have potential use as an antioxidant functional ingredient.