Malt sprouts as a source of supplemental protein for ruminants

Nitrogen solubility, ruminal degradation, and amino acid composition of pelleted malt sprouts, pelleted corn gluten feed, and soybean meal were studied. Four rumen-cannulated steers were fed diets containing 45% pelleted malt sprouts or 45% pelleted corn gluten feed in a 2 X 2 crossover design with 15-d periods. Ruminal degradation of dry matter and nitrogen from malt sprouts or corn gluten feed was estimated by disappearance of these components from polyester bags after 1, 2, 3, 4, 6, 8, 10, 12, 16, or 24 h of in situ fermentation. For comparison, degradation of soybean meal after 2, 4, 8, or 24 h was measured. Malt sprouts had less soluble nitrogen than corn gluten feed, but available crude protein contents were similar. Malt sprouts dry matter was degraded more slowly than was corn gluten feed dry matter. Nitrogen degradation rates of the two feeds, after correction for unavailable nitrogen, did not differ. Malt sprouts had higher concentrations of arginine, lysine, and aspartate than corn gluten feed; however, corn gluten feed had higher concentrations of the other amino acids measured. Malt sprouts would be expected to provide more amino acids of feed origin to the lower gut of ruminants, provided passage rates of the supplements are similar.     

Potential application of microalga Spirulina platensis as a protein source

The high protein level of various microalgal species is one of the main reasons to consider them an unconventional source of this compound. Spirulina platensis stands out for being one of the richest protein sources of microbial origin (460–630 g kg^?1, dry matter basis), having similar protein levels when compared to meat and soybeans. The use of S. platensis in food can bring benefits to human health owing to its chemical composition, since it has high levels of vitamins, minerals, phenolics, essential fatty acids, amino acids and pigments. Furthermore, the development of new protein sources to supply the shortage of this nutrient is an urgent need, and protein from S. platensis plays an important role in this scenario. In this sense, extraction processes that allow maximum protein yield and total utilization of biomass is an urgent need, and ultrasonic waves have proven to be an effective extraction technique. The number of scientific papers related to protein fraction from S. platensis is still limited; thus further studies on its functional and technological properties are needed. © 2016 Society of Chemical Industry     

Full-fat sunflower seed as a protein source for broiler chicks

The protein quality of hulled full-fat sunflower seed (HFFSS) was evaluated and compared to that of soyabean meal in two experiments with broiler chicks. In the first experiment, PER and NPR indexes were determined. The results showed that, when fed as the sole source of dietary protein (90 g crude protein kg⁻¹ diet), the performance as well as PER and NPR values of chicks fed HFFSS were much poorer than those of chicks fed soyabean meal. The protein quality of HFFSS was improved greatly by lysine supplementation. The PER and NPR values for HFFSS supplemented with 0.2 and 0.4% of L -lysine equalled and even became superior to those estimated for soyabean. In the second experiment, apparent and true ileal digestibilities of nitrogen and amino acids were calculated. The apparent but not the true digestibility of the mean of amino acids was significantly lower (P < 0.01) in HFFSS than in soyabean meal (0.838 vs 0.902 and 0.932 vs 0.957, respectively). The results also showed that lysine from HFFSS was less digestible than that from soyabean meal, the apparent as well as the true digestibility values being lower in the former. © 1999 Society of Chemical Industry     

Nutritional evaluation of the fungus Phycomyces blakesleeanus as a protein source

The quality of the protein of the carotenogenic fungus Phycomyces blakesleeanus Burgeff, strain NRRL 1555 ( - ), was evaluated with rats and observed to have a protein efficiency ratio of 1.4. The limiting amino acids were tryptophan, sulphur-containing amino acids, lysine and isoleucine. Upon incorporation into diets containing 100 g kg⁻¹ protein the proportions of the above mentioned amino acids of the optimal recommended dietary allowances for growing rats were 33.0%, 57.4%, 74.5% and 87.2% respectively. Furthermore, the fungal protein was found to contain an excess of histidine about eight fold more than the recommended dietary allowance for growing rats. Some safety aspects were examined and, although the fungus was consumed in high dietary concentrations, 242 g kg⁻¹ of the diet, no pronounced toxicological effects were observed.     

Vicia faba beans vs. soyabean meal as a source of protein

The protein value of raw, heated and shelled Vicia faba beans (VFB) was compared with that of heated soyabean meal (HSB) when fed at 10 and 15% protein levels to rats of both sexes. While females grew equally well on VFB and HSB diets containing 15% protein, males fed VFB grew more slowly than those fed HSB at the two levels of protein in the diets (the difference being smaller on the 15% protein diet). The lower N utilisation of VFB seems to be the main reason for the differences in the growth response. Shelling improved the nutritive value of VFB, while autoclaving affected it adversely. The trypsin inhibitors of the VFB were not destroyed by autoclaving.     

Proteins of Brassicaceae oilseeds and their potential as a plant protein source

Among the commercially cultivated Brassicaceae (Cruciferae) plants, Brassica juncea, Brassica napus, Brassica rapa, and Sinapis alba store significant amounts of oil and protein in the seed. At present, Brassica seed proteins are primarily used for livestock feeding based on the nutritional value. The point of curiosity is whether the present knowledge on the protein structure, biochemical characteristics, nutritive value, and the recovery processes are inadequate to develop Brassica proteins into a usable plant protein source or these proteins are of substandard for uses beyond animal nutrition applications. Cruciferin (11S) and napin (2S) are the predominant storage proteins of Brassicaceae seeds that contribute to different properties and functions. A gamut of information is available on the chemistry, nutritional value, as well as the functionality in foods, and associated non-protein components of canola/rapeseed storage proteins. The intention of this article is to critically review what is known about the predominant storage proteins of commercially produced Brassicaceae seeds relative to the above aspects and identify the knowledge gaps.     

Seaweed as an alternative protein source: Prospective protein extraction technologies

Demand for food production has increased due to population growth. The negative environmental impact of animal agriculture necessitates the search for alternatives to animal protein-based products. Potential health benefits from micronutrient-rich seaweeds have attracted significant attention for further research. This encourages the use of seaweed as an alternative protein-rich source. However, traditional seaweed protein extraction presents drawbacks because of energy and water-intensive treatments and poor extraction yield, which limit their application. There is an urge for cost-effective, novel, and sustainable technologies for seaweed protein extraction at the right techno-economics. Thus, this review article discusses the economic potential of seaweed proteins and identifies the traditional technologies applied to extract seaweed protein and their limitations. A detailed analysis of novel methods that could potentially be utilized to extract and enrich seaweed protein is presented. Various protein quantification/qualification approaches reported in the literature have been thoroughly assessed to compare their advantages and disadvantages. Technologies like the pulsed electric field, ultrasound- and microwave-assisted extraction, high-pressure processing, and subcritical-water extraction have huge potential to extract protein from seaweed sustainably yet are relatively under-explored. More research is required to develop further insights on the process-quality inter-relationship of these technologies for improved seaweed protein extraction. Essential amino acid index, protein digestibility corrected amino acid score, and digestible indispensable amino acid score are the best approaches to evaluate seaweed protein quality for human consumption. However, reported studies have barely covered these aspects, including seaweed protein's sensorial quality.     

Chemical compositions of the marine algae Gracilaria salicornia (Rhodophyta) and Ulva lactuca (Chlorophyta) as a potential food source

BACKGROUND: The nutritional compositions of two edible red (Gracilaria salicornia) and green (Ulva lactuca) seaweeds were determined to evaluate their possible uses as potential food ingredients. RESULTS: In general, these species contained limited amounts of lipids ranging between 0.99 and 2.00 g 100 g^?1 dry weight) and considerably high amount of minerals, especially in G. salicornia (38.91 g 100 g^?1 d.w.). The crude protein values varied between 9.58 and 10.69 g 100 g^?1 d.w. Amounts for total amino acids were 889.78 ± 22.64 mg g^?1 protein d.w. in G. salicornia and 543.3 ± 15.14 mg g^?1 protein d.w. in U. lactuca. The most abundant fatty acids were C12:0, C16:0, C20:4 ω6 and C22:5 ω3, in addition to C18:1 in G. salicornia. Both seaweed species were balanced sources of ω3 and ω6 fatty acids with a ratio of ω6/ω3 that varied between 1.2 and 1.17. Between the seaweeds investigated, high levels of K (2414.02‐11 380.06 mg 100 g^?1 d.w.) were observed and the amounts of Ca, Na and Fe were higher than those reported for land plants. CONCLUSIONS: Thus, G. salicornia and U. lactuca may be utilised as value‐added products for human nutrition purposes. Copyright © 2012 Society of Chemical Industry     

Problems which limit the use of rapeseed meal as a protein source in poultry diets

The occurrence of a ‘fishy’ or ‘crabby’ taint in eggs and liver damage culminating in massive haemorrhage has greatly restricted the commercial utilisation of rapeseed meal as a relatively cheap protein supplement for laying hens in the UK. Recent work on these problems is reviewed. It has elucidated the cause of the taint and identified the rapeseed constituents that are involved. A genetic defect impedes the synthesis of trimethylamine oxidase in susceptible hens and goitrin and tannins inhibit the enzyme. This biochemical lesion severely impairs the metabolism of trimethylamine which is released from sinapine and other dietary sources of choline by enteric bacteria. Consequently, excessive amounts pass into the yolk and produce the taint. Liver haemorrhage is associated with hepatocyte degeneration, abnormalities in the biliary system and the leakage of cellular enzymes into the plasma. The toxic substance(s) responsible has (have) not yet been identified.     

Waste from brewing (trub) as a source of protein for the food industry

The use of agro-industrial waste for food enrichment can be limited, due to taste, odour, colour and other unpleasant characteristics. Trub (brewing waste) has important nutrients, such as proteins and carbohydrates, and phytochemical compounds; however, its applications are hindered by the astringent flavour. In order to reduce the bitterness of trub, aqueous extractions were realized at high temperature (100 °C per 1 h) in five steps. Two fractions were obtained; a liquid fraction (containing bitter compounds) and a solid fraction (the trub after the extraction process; TAP). Both fractions and the trub before the extraction process (TBP) were evaluated. The bitterness of TBP was significantly reduced in TAP while the protein content increased; TAP presented a branched network and changes in its structure. The reduction in bitterness and the high protein content allows the use of trub in the food industry.     

Scallops as a new source of food protein: high-intensity ultrasonication improved stability of oil-in-water emulsion stabilised by myofibrillar protein

In this study, the effect of high-intensity ultrasound (HIUS) (200 and 400 W for 0, 5, 10 and 15 min respectively) on conformational changes, physicochemical, rheological and emulsifying properties of scallop (Patinopecten yessoensis) myofibrillar protein (SMP) was investigated. HIUS-treated SMP had lower α-helix content and higher β-sheet content compared with the native SMP. HIUS treatment induced the unfolding of SMP and increased the surface hydrophobicity. The particle size of SMP decreased and the absolute zeta-potential increased after ultrasonication, which in turn increased the solubility of SMP. The conformational changes and the improvement of physicochemical properties of SMP increased the ability for SMP to lower the interfacial tension at the oil–water interface and increased the percentage of adsorbed protein. As a result, the emulsifying properties, rheological properties of SMP and storage stability of emulsions were also improved. In conclusion, HIUS treatment has future potential for improving the emulsifying properties of SMP.     

Evaluation of calcium lignosulfonate-treated soybean meal as a source of rumen protected protein for dairy cattle

Four Holstein cows fitted with ruminal, duodenal, and ileal cannulae were used in a 4 x 4 Latin square design to measure ruminal protein degradation and small intestinal digestion of diets containing untreated soybean meal or soybean meal treated with heat and either water, xylose, or calcium lignosulfonate. Diets consisting of 40% corn silage, 10% alfalfa cubes, and 50% grain mix, and averaging 16.8% crude protein (DM basis) were fed four times daily. Approximately 50% of the total dietary protein was supplied by the respective soybean meal source. Ruminal protein degradation was 70.6, 69.6, 55.8, and 53.7% for diets containing untreated soybean meal, water-soybean meal, xylose-soybean meal, and calcium lignosulfonate-soybean meal, respectively. Duodenal non-NH3 N flow (g/d) and absorption of non-NH3 N (g/d) in the small intestine were generally not affected by treatment. Duodenal bacterial N flow (g/d) was lower with xylose-soybean meal and lignosulfonate-soybean meal than with untreated soybean meal. Treatment of soybean meal with xylose or calcium lignosulfonate was successful in decreasing ruminal protein degradation. However, it may be necessary to include a source of readily fermentable N in diets that contain protected proteins in order to supply adequate NH3 N for microbial protein synthesis.     

Celery by-products as a source of mannitol

Vegetable by-products have mainly been utilized as a source of dietary fiber and natural antioxidants, but residual vegetables could also be used as a raw material for soluble sugar and polyol extraction. Therefore, two celery residues from the food industry, composed either of stalks alone or stalks plus leaves, were extracted with hot 85% ethanol to solubilize soluble sugars and mannitol. Low-molecular-weight carbohydrates in the extracts were identified and quantified by high-performance liquid chromatography. Both celery residues contained similar amounts of sucrose (5.7-5.9%), but different ratios of hexose (glucose and fructose) to mannitol. Total sugar content and mannitol were higher in the stalks (45.5% and 15.2%, respectively) than in the stalk plus leaf residues (33.9% and 13.3%, respectively). Mannitol represented 33.5-39.3% of the total carbohydrate in celery wastes. The alcoholic extracts from celery residues are proposed as a natural source of mannitol and soluble sugars, which might be used by the food industry. The alcohol-insoluble residue from celery by-products could be further used for the preparation of dietary fiber-rich food supplements.