Hull Fractions Research Articles

Factors that affect the nutritive value of canola meal for poultry

This article reviews the factors affecting the nutritive value of canola meal (CM), including glucosinolates, sinapine, phytic acid, tannins, dietary fiber, and electrolyte balance. It also addresses the means of improving the nutritive value of CM throughout seed dehulling, development of low-fiber canola, or application of feed enzymes. Over the years, the glucosinolate content of canola has been declining steadily and is now only about one-twelfth of that of the older high-glucosinolate rapeseed (that is, 10 vs. 120 μmol/g). Therefore, the rations for broilers or laying hens could now contain 20% of CM without producing any adverse effects. Tannins are of lesser importance due to their presence in the hull fraction and thus low water solubility. Sinapine has been implicated with the production of a "fishy" taint in brown-shelled eggs, which results from a genetic defect among the strain of Rhode Island Red laying hens. The White Leghorns have been reported not to be affected. Although lower in protein, CM compares favorably with soybean meal with regard to amino acid content. Because CM contains more methionine and cysteine but less lysine, both meals tend to complement each other when used together in poultry diets. Canola meal is low in arginine (Arg) which could be of importance when introducing CM to broiler diets at high inclusion rates. The Arg content of CM is approximately two-thirds of that of soybean meal. Chickens fail to synthesize Arg and are highly dependent on dietary sources for this amino acid. Supplementation of Arg to CM-based diets has been shown to partly restore the growth performance. Dietary cation-anion difference in CM is also less than optimal due to the high sulfur and low potassium contents. Seed dehulling has not been very successful due to excessive fineness and thus difficulties with percolation of the miscella through the cake. Development of low-fiber, yellow-seeded canola and the use of enzymes have proven to increase the energy utilization and the nutritive value of CM for poultry.

Phenolic acids and antioxidant properties of barley wholegrain and pearling fractions

Demand for functional foods that offer therapeutic and disease-prevention properties is globally increasing. Barley presents an opportunity in this regard due to its high antioxidants and dietary fiber contents. Barley wholegrain and milling fractions were investigated in terms of phenolic acids composition, scavenging capacity against DPPH and ABTS radicals and inhibition of human LDL oxidation in vitro. Ferulic and p-coumaric were the primary phenolic acids in wholegrain and pearled fractions accounting for 43-97% and 2-55% of total phenolic acids, respectively. This wide range demonstrates significant differences among barley wholegrain or pearled products. Antioxidant capacities also varied significantly among barleys with the hulless cultivars tested exhibiting the greatest. The outer layers fraction showed higher scavenging capacity against ABTS and DPPH radicals and inhibitory effects toward LDL oxidation compared with the endosperm fractions. The results suggest that the outer layer and hull fractions would potentially provide promising sources of natural antioxidants.

Improved Estimation of Oil, Linoleic and Oleic Acid and Seed Hull Fractions in Safflower by NIRS

Near-infrared reflectance spectroscopy (NIRS) of intact seeds allows the non-destructive estimation of seed quality parameters which is highly desirable in plant breeding. Together with yield, oil content and quality, a main aim in safflower (Carthamus tinctorius L.) breeding is the selection of genotypes with a low percentage of empty seeds even under cooler climates. We developed NIRS calibrations for seed oil content, oleic and linoleic acid content, the seed hull fraction and the percentage of empty seeds using seed meal and intact seeds. For the different calibrations 108–534 samples from a safflower breeding program with lines adapted to German conditions, were analyzed with reference analyses (Soxhlet, gas chromatography), and scanned by NIRS as intact seeds and seed meal. Calibration equations were developed and tested through cross validation. The coefficient of determination of the calibration (R 2) for intact seeds ranged from 0.91(oil content), 0.90 (seed hull fraction), 0.84 (empty seeds), 0.73 (linoleic acid) to 0.68 (oleic acid). The coefficient of determination of the cross validation was higher for seed meal than for intact seeds except for the parameter seed hull fraction. The results show that NIRS calibrations are applicable in safflower breeding programs for a fast screening.

Bioactivities and Antiradical Properties of Millet Grains and Hulls

Antioxidant activities of phenolic extracts of kodo and pearl millet whole grains, dehulled grains, and hulls were examined by monitoring inhibition of radical-induced DNA scission, human low-density lipoprotein (LDL) cholesterol, and phospholipid liposome oxidation. Total phenolic content (TPC), hydroxyl and peroxyl radical inhibition, and antiproliferative activities against HT-29 cells were also determined. Major hydroxycinnamic acids in dehulled grains and hulls were identified and quantified using HPLC. Phenolic extract of kodo millet exhibited higher inhibition activities against oxidation of LDL cholesterol and liposome than that of pearl millet. All phenolic extracts exhibited a dose-dependent inhibition of DNA scission. The TPC of hulls of kodo and pearl millets were 3 times higher than those of their corresponding whole grains. At the end of 96 h of incubation, kodo millet extracts inhibited cell proliferation in the range of 75-100%. Antioxidant activities of phenolic extracts were in the order hull > whole grain > dehulled grain. Dehulling reduced the antioxidant potential of whole millet grains. Ferulic and p-coumaric acids were the major hydroxycinnamic acids, and their contents ranged from 17.8 to 1685 μg/g defatted meal and from 3.5 to 680 μg/g defatted meal, respectively. Dehulled grains, as well as the hull fraction, may serve as potential sources of nutraceutical and functional food ingredients in health promotion.

Degradation of acephate and its metabolite methamidophos in rice during processing and storage

The degradation of acephate and its metabolite methamidophos during different stages of commercial processing, homing processing, and storage was assessed. Residues were determined by a simple gas-chromatographic method using a flame photometry detector. Acephate and methamidophos mostly remained in rice hull fractions, and hulling significantly reduced acephate and methamidophos in rice. Commercial processing caused the loss of 86% of acephate and 35.9% of methamidophos from rough brown rice to polished rice, whereas home processing caused the loss of 83.9% of acephate and 70% of methamidophos from polished rice to cooked rice. Washing for 5, 15, and 30 min (with tap water, 0.9% NaCl, and 0.1% Na2CO3) caused an average loss in the range of 9.8%–35.3% of acephate and 9.7%–45.2% of methamidophos. Extending washing time and adding a small amount of soda into the washing solution can efficiently eliminate acephate and methamidophos. The stability of acephate and methamidophos in polished rice was studied at different storage intervals, from 7 to 42 days at ambient temperatures (25 °C). Methamidophos was found to be more persistent than acephate.

Hepato-protective Potential of Hull Fraction from Indian Flaxseed Cultivar

Objective: Secoisolariciresinol diglucoside (SDG) isolated from hull fraction of Indian flaxseed cultivar was studied for its hepatoprotective potential by measuring the level of hepatic enzymes such as catalase, peroxidase and superoxide desmutase (SOD) upon feeding to albino rats. Material & Methods: The animals were grouped into five groups (n=5): The first group served as normal and received normal diet without treatment of toxin and hull fraction of flaxseed. The second group was named the control and received a regular commercial diet. The third, fourth and fifth groups were fed with normal diet and supplemented with hull fraction of flaxseed (150 and 250 μg/kg) and standard SDG (150 μg/kg), that was mixed with olive oil for 14 days. Results: Pretreatment of rats with 150 μg/kg b.w hull fraction of flaxseed followed by CCl4 treatment caused restoration of catalase, SOD and peroxidase by 37.70%, 108.22% and 23.89% respectively as compared to control. The group treated with 250 μg/kg b.w hull fraction of flaxseed showed the restoration of 67.30%, 152.82% and 39.88% of catalase, SOD and peroxidase, respectively. Conclusion: In conclusion, SDG fed in the form of flaxseed hull is responsible for its hepatoprotective properties. Further, it can be used as a potential source of nutraceutical agent and studies are required in this field to examine its use in large scale for food and feed industries.Keywords: Flaxseed; hull fraction; SDG; antioxidant enzymesDOI: 10.3126/ajms.v1i2.2938Asian Journal of Medical Sciences 1 (2010) 20-25

Progressive Hull Removal from Barley using the Fitzpatrick Comminuting Mill

The objective of the study was to explore the use of the Fitzpatrick Comminuting Machine (FitzMill®) to remove the hull from hulled barley while keeping the barley kernel intact, thereby avoiding starch loss. Traditionally, this mill is used to grind material, but we have discovered that it can precisely shear the hull from the kernels using the sharp end of the blades. Different residence times in the mill were compared, and chemical analysis of hull and de-hulled kernel fractions, as well as rates of progressive hull removal, were studied to determine optimal settings. While whole kernels had only about 60% starch content, de-hulled barley kernel fractions had starch contents of over 71%, which are comparable to high-starch grains, such as corn, which are more efficient for fuel ethanol production. Furthermore, corresponding hull fractions contained less than 6% starch which translates to less than 1.5% starch loss from the original kernel. De-hulling will make a significant improvement to the barley's value as a feedstock for fuel ethanol production, increasing the starch content by 11 percentage points, and simultaneously decreasing non-fermentable fractions by a similar level. With a method to fractionate hulled barley into high-starch fractions (de-hulled kernels) and fiber rich hulls, hulled barley becomes a more desirable feedstock for fuel ethanol production. Also, since hulls would be removed prior to ethanol production they would be available for conversion into other valuable coproducts.

Evaluating the Quality of Protein from Hemp Seed (Cannabis sativa L.) Products Through the use of the Protein Digestibility-Corrected Amino Acid Score Method

The macronutrient composition and the quality of protein of hemp seed and products derived from hemp seed grown in Western Canada were determined. Thirty samples of hemp products (minimum 500 g), including whole hemp seed, hemp seed meal from cold-press expelling, dehulled, or shelled, hemp seed and hemp seed hulls, were obtained from commercial sources. Proximate analysis, including crude protein (% CP), crude fat (% fat) and fiber, as well as full amino acid profiles, were determined for all samples. Protein digestibility-corrected amino acid score (PDCAAS) measurements, using a rat bioassay for protein digestibility and the FAO/WHO amino acid requirement of children (2-5 years of age) as reference, were conducted on subsets of hemp products. Mean (±SD) percentage CP and fat were 24.0(2.1) and 30.4(2.7) for whole hemp seed, 40.7(8.8) and 10.2(2.1) for hemp seed meal, and 35.9(3.6) and 46.7(5.0) for dehulled hemp seed. The percentage protein digestibility and PDCAAS values were 84.1-86.2 and 49-53% for whole hemp seed, 90.8-97.5 and 46-51% for hemp seed meal, and 83.5-92.1 and 63-66% for dehulled hemp seed. Lysine was the first limiting amino acid in all products. Removal of the hull fraction improved protein digestibility and the resultant PDCAAS value. The current results provide reference data in support of protein claims for hemp seed products and provide evidence that hemp proteins have a PDCAAS equal to or greater than certain grains, nuts, and some pulses.

Effect of pea, pea hulls, faba beans and faba bean hulls on the ileal microbial composition in weaned piglets

Grain legumes produced in Europe such as pea, faba beans and lupins are alternative vegetable protein sources for imported soy protein in animal feeds. These legume seeds contain constituents that are not digested and may act as a substrate for microbial fermentation in the gastrointestinal tract, thereby modulating the microbial population and affecting the microbial diversity. In this study the effect was evaluated of inclusion of pea and faba beans and their hull fractions in diets for piglets on the intestinal microbial population at the ileal level. A total of 72 piglets weaned at 28 days of age were fed a control diet based on soybean meal or diets with pea (250 g/kg), pea hulls (100 g/kg), faba beans (250 g/kg) or faba bean hulls (100 g/kg). All piglets were challenged orally with an enterotoxigenic Escherichia coli (ETEC) 7 days after weaning, except for half of the piglets fed the soybean meal diet that were inoculated with phosphate buffered saline. The piglets were sacrificed 21 days after weaning and ileal digesta samples were collected and analysed with a terminal restriction fraction length polymorphism based method of Microbial Community Profiling and Characterization. From 10 days after the challenge, there was no faecal excretion of ETEC in any of the piglets. There was a distinct different microbial profile in the piglets fed the diet with faba beans or faba bean hulls, showing a lower number of terminal restriction fragments (T-RFs) compared to the other treatments. Such an alteration in the ileal microflora composition by the use of different legume seeds or their hull fractions suggests a potential for the manipulation of intestinal microbial activity and thus in preventing or provoking intestinal disorders in piglets.

Effects of Phytases and Dehulling Treatments on In Vitro Iron and Zinc Bioavailability in Faba Bean (Vicia faba L.) Flour and Legume Fractions

In vitro digestions were performed on faba bean flours with decreased phytate contents and on 2 dephytinized or nondephytinized faba bean fractions, a dehulled faba bean fraction, and a hull fraction with low and high fiber and tannin contents, respectively. In vitro bioavailability iron and zinc was defined as the relative amount of iron and zinc that became soluble after enzymatic treatment. Faba bean samples were sequentially digested with enzymes, including amylase, pepsin, pancreatin, and bile, under certain conditions following the enzymatic degradation procedure. Iron and zinc in vitro bioavailability of whole faba bean flours were significantly improved by phytate degradation, even if the phytate were not all degraded. Total dephytinization of dehulled faba bean led to an obvious increase in iron and zinc in vitro bioavailability, but that of hulls had no effect on either iron or zinc in vitro bioavailability. Fibers and tannins other than phytate are more important in chelating a high proportion of iron and zinc in faba bean hulls.

Effects of phytase, cellulase and dehulling treatments on zinc in vitro solubility in faba bean (Vicia faba L.) flour and seed fractions

SummarySimulations of gastro‐intestinal digestion was used to try to identify the nature of the complexes between antinutritional factors and zinc in faba bean fractions. In the hull fraction, the action of phytases and the simultaneous action of cellulase and phytase allowed about 7% and 35% additional zinc to be solubilised, respectively. Single enzymatic degradation of phytates from dehulled faba bean allowed solubilisation from 65% to 93% of zinc depending upon the treatment. The zinc of faba bean flour was mainly linked to phytates and the greater the degree of phytate degradation before in vitro digestion, the greater the quantity of zinc released. In dehulled faba bean zinc was almost exclusively chelated by phytates. In the hull of faba bean, the majority of zinc was chelated in complexes between phytates and fibres.

Effects of Phytase, Cellulase, and Dehulling Treatments on Iron and Zinc in Vitro Solubility in Faba Bean (Vicia faba L.) Flour and Legume Fractions

Simulations of gastrointestinal digestion were used to try to identify the nature of the complexes between antinutritional factors and iron and zinc in faba bean and legume fractions. In digestible residue of raw faba bean flour, simultaneous action of cellulase and phytases made it possible to release about 28% units more iron than that released with the treatment without enzymes. About 49.8% of iron in raw faba bean flour was solubilized after in vitro digestion and simultaneous action of cellulase and phytase. In the hull fraction, the action of phytases and the simultaneous action of cellulase and phytase allowed about 7 and 35% units of additional zinc to be solubilized, respectively. Single enzymatic degradation of phytates from dehulled faba bean allowed solubilization from 65 to 93% of zinc, depending upon the treatment. In dehulled faba bean, iron was chelated by phytates and by fibers, whereas zinc was almost exclusively chelated by phytates. In the hull of faba bean, a high proportion of iron was chelated by iron-tannins, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers.

In vitro Viscosity as a Function of Guar Meal and ß-Mannanase Content of Feeds

Guar meal, a high protein by-product of guar gum production can be separated into germ and hull fractions. Guar meal at high concentrations in the diet depresses growth and feed efficiency of chickens. The gum, a galactomannan polysaccharide increases intestinal viscosity and thereby decreases nutrient absorption. Guar gum residue is the presumptive anti-nutritive factor in guar meal. An in vitro procedure was developed to measure the impact of guar meals and endo-s-mannanase (Hemicell ) on feed viscosity. s- ® w/v) and incubated. Subsequently, samples were centrifuged and supernatant viscosity measured. Supernatant viscosity increased in direct proportion to guar meal concentration. Hull fraction increased viscosity more than the germ fraction. s-mannanase significantly reduced the viscosity of all diets except the 2.5% germ fraction diet. An inverse relationship was observed between enzyme concentration and sample viscosity from 0 to the recommended enzyme level. Enzyme concentrations exceeding the recommended level did not further reduce viscosity of feed supernatant. These results are consistent with feed viscosity as the basis of feed efficiency improvement with enzyme feeding. Increased viscosity with guar meal inclusion and reduced viscosity with enzyme inclusion is consistent with the hypothesis that feed viscosity is the anti- nutritive effect of guar meal feeding.

Demucilaging and dehulling flaxseed with a wet process

A continuous wet process for demucilaging and dehulling of flaxseeds was proposed to recover mucilage fraction and hull fraction from flaxseed. Mucilage was obtained by aqueous extraction and demucilaged flaxseeds were milled and fractionated by water separation in mixing tanks. Hull-rich, kernel-rich and an inseparable fraction were obtained with yields of 52.6, 22.3 and 12.7 g/100 g, respectively, when disk gap was set as 0.4 mm. The hull content of kernel-rich fraction and kernel content of hull-rich fraction were determined as 20.9 and 11.1 g/100 g, respectively. Although 11.5% oil, 15.3% protein and 9.6% secoisolariciresinol diglucoside (SDG) were lost during the demucilaging and dehulling of flaxseed, SDG was enriched in the hull-rich fraction and the inseparable fraction, while flaxseed oil in the kernel-rich fraction. Compared with dry processes, the proposed wet process is time-consuming and requires substantial amount of water. However, it is continuous and easy to scale up, and can be economical when an aqueous extraction of oil is used. It is also a good alternative for recovery of flaxseed gum and enrichment of SDG.

Effects of Selected Barley Cultivars and Their Pearling Fractions on Inhibition of Human LDL Oxidation In Vitro Using a Modified Conjugated Dienes Method

ABSTRACTOxidation of LDL cholesterol is an important factor in the development of atherosclerosis and heart disease. In this study, selected Canadian and Egyptian barley cultivars and their pearling fractions were evaluated for antioxidant capacity to inhibit human LDL oxidation in vitro. Measurement of conjugated dienes (CD) at 234 nm was optimized to determine the degree of LDL oxidation. Dilution of oxidized LDL with iso‐propanol gave a distinct diene conjugation peak. Significant differences in total phenols content (TPC) were found between the cultivars tested, with the hulless barley having greater TPC and inhibition capacity compared with hulled barleys. The outer layers fraction contained the highest TPC, lowest CD formation, and longest lag time, whereas the inner, or endosperm fraction, had the lowest inhibition effects. The middle pearling and hull fractions possessed intermediate inhibition effects. The inhibitory effect of barley extracts was dependent on phenols concentration following a linear or quadratic pattern. The results suggest that barley whole meals, outer layers, middle pearling, or hull fraction would be a potential LDL antioxidant.

Antioxidant activity of white and black sesame seeds and their hull fractions

The total phenolic content (TPC), total antioxidant status (TAS), free radical scavenging capacity, inhibition of low density lipoprotein (LDL) cholesterol and metal chelating capacity of extracts of whole black and whole white sesame seeds and their hull fractions in 80% aqueous ethanol were investigated. The TPC of whole black sesame seeds and hull extracts were 29.9 ± 0.6 and 146.6 ± 0.6 mg catechin equivalents/g crude ethanolic extract, respectively. The corresponding values for white sesame were 10.6 ± 1.6 and 29.7 ± 0.9 mg catechin equivalents/g crude ethanolic extract. The TAS as determined by Trolox equivalent antioxidant capacity assay and expressed as Trolox equivalents was highest for black sesame hulls (65.9 ± 1.7) while white seeds showed the lowest (4.4 ± 0.6). Free radical scavenging capacity of sesame extracts (5–40 μg/mL) was measured using 2,2-diphenyl-1-picrylhydrazyl radical. The highest scavenging capacity was obtained at 40 μg/mL and was 94.9 ± 0.8, 25.1 ± 0.4, 14.4 ± 0.9 and 2.5 ± 0.4 for black sesame hulls, black sesame seeds, white sesame hulls and white sesame seeds, respectively. Inhibition of LDL oxidation at 100 ppm level was highest for black sesame hulls (96.7%) followed by those for white sesame hulls (84.6%), black sesame (78.4%) and white sesame seeds (57.3%). Sesame products displayed good ferrous ion chelating capacities, which ranged from 12% to 46% and 17% to 62% at 50 and 100 ppm levels, respectively. Results demonstrated considerable antioxidant activity of sesame products tested especially black sesame hulls.

Effects of guar meal by-product with and without beta-mannanase Hemicell on broiler performance

Guar gum production yields a high protein guar meal that can be subdivided into germ and hull fractions. Feeding high concentrations of guar meal reduces body weight and feed efficiency in chickens due to the presence of a residual guar gum. Two experiments determined the upper feeding levels of guar meal and the hull and germ fractions in broiler chickens. An industrial source beta-mannanase (Hemicell) also was fed in combination with guar meals. Experiment 1 utilized a 3 × 4 factorial design to feed broiler chickens diets containing guar germ, guar hull, or guar meal at 4 levels (2.5, 5.0, 7.5, and 10.0%) compared with a negative control diet. Results indicated that any of the 3 guar meals could be fed at a 2.5% dietary inclusion rate without adversely affecting broiler chicken growth to 6 wk of age. In experiment 2, a 4 × 2 factorial design consisting of the 3 by-products meals at 5% inclusion and soybean meal control with and without enzyme tested whether Hemicell could increase inclusion rates without decreasing broiler growth or feed consumption to 6 wk of age. Addition of Hemicell to feed had no effect on measures of growth in chickens fed the control diet. Hemicell significantly improved feed:gain ratio of diets containing 5% of each fraction of guar meal versus the untreated diets. Feed:gain ratio for the Hemicell-treated 5% germ fraction diet was improved to control diet levels. Results indicated that the upper feeding level of guar meal and germ and hull fraction of guar meal is 2.5%, and addition of beta-mannanase (Hemicell) increases the upper feeding level for the germ fraction to 5%.

Comparison between Peat and Fresh Rice Hulls: Hydraulic and Chemical Characteristics

One of the most widely used substrates in nursery production is peat, which is used as plain substrate or mixed with other media. Peat use is problematic, primarily because of the high price and the environmental implications connected with its extraction and disposal. For these reasons, the exploitation will be restricted in the future in both Europe and America. Thus, researchers are under pressure to find alternative substrates that can be used in an inexpensive and environmentally friendly way. Although aged, carbonized and composted rice hulls have been used to a limited extent, more studies are needed to characterize fresh rice hulls as a growing medium. This research was aimed at characterizing fresh hulls after being ground in different particle sizes, and comparing them with peat. Ground hulls were separated into four fractions (6-, 4-, 2-, and 1-mm diameter), which were characterized for pH, EC, CEC, organic matter, and total nitrogen content. The water retention curve was also estimated and the following hydraulic characteristics were measured and compared: TP, CC, AFP, EAW, and WBC. As expected, pH, N, and C content and CEC did not differ among rice hull fractions, while EC showed a slight but constant increase when particle dimensions decreased. Compared to peat, the TP of rice hulls was smaller independently from particle dimensions, but AFP was 19.5%, 44,1%, 114.2%, and 115.8% higher for 1-, 2-, 4-, and 6-mm particles, respectively, indicating a very good aeration capacity. EAW and WBC were higher only in 1- and 2-mm particles. A further experiment aimed at comparing the behavior of transplants in rice hulls (6 mm) and peat showed that tomato plantlets grew slower in the former, although transplants were of good, marketable quality.

Antioxidant Potential of Pea Beans (Phaseolus vulgaris L.)

ABSTRACT: Four bean varieties (Phaseolus vulgaris L.) (white kidney, red pinto, Swedish brown, and black kidney) and their hull fractions were extracted with 80% acetone and evaluated for their phenolic contents and antiradical activities. Total phenolic content of bean hulls and whole seed extracts ranged from 6.7 to 270 and 4.9 to 93.6 mg/g extract as catechin equivalents, respectively. Trolox equivalent antioxidant capacity (TEAC) assay revealed that the antioxidant capacity of red, brown, and black whole seed extracts was in the same order of magnitude with little variation. TEAC values of red and brown whole seed extracts were superior to that of black whole seed extract. On the basis of the total phenolic content and TEAC values, it can be deduced that colored beans possess superior antioxidative activity compared with white beans. The hydrogen peroxide scavenging capacity of different bean extracts ranged from 58% to 67% at 50 ppm and 65% to 76% at 100 ppm. The corresponding superoxide radical scavenging capacity was 24% to 29% at 50 ppm and 53% to 60% at 100 ppm. The 2,2–diphenyl-1–picrylhydrazyl (DPPH) radical scavenging capacity of black bean whole seed extracts was 22% at 50 ppm, whereas the other extracts showed 100% scavenging of this radical at both 50 and 100 ppm levels. The hydroxyl radical scavenging capacities of the bean extracts at 50 and 100 ppm were 12% to 29% and 32% to 49%, respectively. All extracts used prevented human low-density lipoprotein (LDL) cholesterol oxidation by 61.4% to 99.9% at 2 to 50 ppm level as catechin equivalents.

Quantitative Measurement of Negligible Trypsin Inhibitor Activity and Nutrient Analysis of Guar Meal Fractions

A complete nutrient characterization of three possible products of guar bean processing does not apparently exist in the literature. Guar meal is a high-protein byproduct produced during extraction of galactomannan gum from the guar bean. During the extraction process, two fractions are produced (germ and hull). Germ and hull fractions are usually combined to form the marketed product, guar meal. Analyses characterized the nutrient, trypsin inhibitor, and galactomannan gum content of the three guar meal byproducts to determine which fraction is more valuable as an ingredient in poultry diets. Analyses indicated that the germ fraction is most appropriate for inclusion in poultry diets. Trypsin inhibitor activity previously reported as an antigrowth factor associated with guar meal was negligible and not considered to be a significant factor limiting its use in poultry feeds.