Some nutritional properties of the seeds of three Mucuna species

The seeds of Mucuna nivea, M. pruriens and M. utilis showed ash 4.3-5.1%, oil 4.9-5.5%, protein 25.9-27.5%, L-dopa 3.6-4.2%, trypsin 28.5-39.7 mg/g and chymotrypsin inhibitor activity 19.3-24.6 mg/g. The trypsin and chymotrypsin inhibitor activity increased in pod hull and seeds while the amount of protein increased in seeds and decreased in pod hull with maturity. The essential amino acid profile was comparable to the FAO pattern (lysine 6.0-6.4%). The fatty acid composition had total unsaturated acids 51.9-55.9%, but were poor in oil contents.     

Underutilised legumes: potential sources for low-cost protein

Seeds of 104 leguminous species belonging to 17 genera were analysed for their protein contents. The promising ones were investigated for fibre, carbohydrate, ash, oil, fatty acids, amino acid profile and trypsin inhibitor activity (TIA). The variation of fibre contents was 4.1-8.9%, carbohydrate 18.4-49.2%, ash 1.8-7.2%, TIA 48.7-87.5 mg/g, oil 1.3-19.8% and protein 11.0-51.6%. The protein content (41-45%) in Acacia mellifera (41.6%), Albizzia lebbek (43.6%), Bauhinia triandra (42.7%), Lathyrus odoratus (42.8%), Parkinsonia aculeata (41.6%), Psophocarpus tetragonolobus (41.9%), Sesbania paludosa (41.2%) and S. sesban (43.8%) was in close proximity to soybean (42.8%), whereas Bauhinia retusa (51.6%), B. variegata (46.5%), Delonix elata (48.7%) and Gliricidia maculata (46.3%) showed higher percentages of protein than soybean. The essential amino acid composition of some of the seed proteins was reasonably well balanced (lysine up to 7.6%). The seeds of Bauhinia retusa (18.6%), B. triandra (16.5%), B. variegata (17.3%), Gliricidia maculata (16.2%), Parkia biglandulosa (18.9%) and Psophocarpus tetragonolobus (19.8%) had a good amount of oil, comparable to soybean (18-22%). The fatty acid composition of some genera/species was quite promising with high amount of unsaturated fatty acids.     

Nutritional quality of sandbox tree (Hura crepitans Linn.)

Antinutrient, proximate, mineral, fatty acid, vitamin, and amino acid analyses of sandbox tree (Hura crepitans) seeds were carried out. The results of antinutrient analysis showed that H. crepitans seed contains alkaloid (5.0 +/- 0.2 mg/100 g), tannins (5.0 +/- 0.3 mg/100 g), phytate (53.0 +/- 6.0 mg/100 g), cardiac glycoside (1890.0 +/- 1.5 mg/100 g), and saponin (2.2 +/- 0.1 mg/100 g). Its trypsin inhibitor activity was found to be 30.27 +/- 1.86 TIU/mg of protein. The results of proximate analysis showed that H. crepitans seed is very rich in crude protein (25.16 +/- 0.22%), crude oil (51.43 +/- 0.22%), and energy content (2,621.891 +/- 6.357 kJ/100 g). H. crepitans seed also contains 1.85 ppm Na, 3.4 ppm K, 0.088 ppm Ca, and trace amounts of Mg, Fe, and Zn. The results also showed that H. crepitans oil contains 20.12% oleic acid, followed by stearic acid (3.0%), while linoleic acid is present at the lowest level (0.03%) among the other acids. The Hura oil has a high saponification value (127.16 +/- 0.18 mg/g) and low acid value (3.56 +/- 0.16 mg/g). The results also showed that the average molecular weight of glycerides is higher in the oil as reflected by the ester value (123.6 +/- 0.73 mg/g). The iodine value of Hura oil was found to be 65.62 +/- 0.73%. A low peroxide value (6.6 +/- 0.2 mg/g) was observed in Hura oil. The results showed that H. crepitans seed contains 328.1 IU of vitamin A/100 g, 0.398 mg of vitamin E/100 g, and 0.26 mg of vitamin K/100 g. The results also showed that H. crepitans seed is very rich in glutamate (14.41 g/100 g of protein) and deficient in cysteine (0.78 g/100 g of protein). Among the essential amino acids, arginine has the highest value (5.97 g/100 g of protein). This is followed by leucine, at 4.16 g/100 g of protein. Therefore, H. crepitans seed is a nutritionally promising seed.     

Nutrient composition and biological evaluation of an unconventional legume,Canavalia cathartica of mangroves

Seeds of an unconventional legume, Canavalia cathartica from the mangroves of the southwest coast of India, were screened for proximate composition, minerals, protein fractions, amino acid profiles, fatty acids and some anti-nutritional factors. The seeds consisted of 31.2%, 1.86%, 61.4% and 1580 kJ crude proteins, crude lipid, crude carbohydrates and calories, respectively. The crude protein content of seeds was higher than common cereals, whole-wheat flour (8.55%), parboiled rice (7.7%) and egg (12.6%). Essential amino acids, threonine, cysteine?+?methionine, isoleucine, tyrosine?+?phenylalanine and lysine were higher than Food and Agricultural Organization of United Nations/World Health Organization patterns. On comparing the amino acid profile of mangrove and sand dune C. cathartica seeds, the latter were found to be superior (total amino acid content, 123.5% versus 60.8%), while the result was vice versa with respect to the polyunsaturated/saturated ratio (105.9 versus 2.52). The seeds possessed 1420 mg/100 g total phenolics and strong hemagglutination activity, while tannins and trypsin inhibition activity were absent. Physical, nutritional and anti-nutritional features of seeds of C. cathartica of the mangrove have been compared with those of C. cathartica of the sand dunes of the southwest coast of India. A significant difference (P?<?0.05) was observed between the physical, proximal and mineral composition except for ash, magnesium and copper. The protein efficiency ratio, food efficiency ratio, net protein retention, protein retention efficiency, biological value, net protein utilization and true digestibility of C. cathartica seeds were significantly different (P?<?0.05) from casein. In spite of the high protein content, animal-feeding trials indicated low nutritional quality. Nutritional, anti-nutritional factors and protein qualities of seeds C. cathartica have been discussed in comparison with other species of Canavalia.     

Chemical composition of winged bean (Psophocarpus tetragonolobus) varieties

The chemical composition of dry seeds of four varieties, pods, stalks and leaves of winged beans (Psophocarpus tetragonolobus) was determined. The seeds had a high range of protein (27.8-36.6%) and fat (14.8-17.9%), which were similar to soybeans. the seeds contained high phosphorus, calcium and magnesium. The leaf was highest in protein content (33.7%) of all the parts studied except for the seeds. The protein and fat content of pods decreased as pods ripened. the calcium content in the leaf was much higher than in the other parts. Protein was extracted sequentially with 2% NaCl, 30% isopropyl alcohol, 4% lactic acid and 0.5% KOH from dry seeds of four varieties of winged beans. The NaCl extract showed the highest range of protein concentration (60.2-77.6%). The NaCl extract was separated into two fractions based on solubility in water. the amino acid composition of the flour from the seeds and of the two fractions from the NaCl extract were determined. Contents of lysine, aspartic acid, glutamic acid and leucine were large, while the sulfur-amino acid content was small. Trypsin and chymotrypsin inhibitory activities of 2% NaCl extract from the seeds were determined, and chymotrypsin inhibitory activity was higher than the trypsin.     

Analysis of components and study on antioxidant and antimicrobial activities of oil in apple seeds

Abstract

In order to improve the comprehensive utilization of major by-products in apple-juice processing, the components, antioxidant and antimicrobial activities of oil in two species apple seeds, Fuji and New Red Star, were investigated. The Soxhlet extracted oil content of apple seeds raged from 20.69 to 24.32 g/100 g. The protein, fiber and ash contents were found to be 38.85–49.55 g/100 g, 3.92–4.32 g/100 g and 4.31–5.20 g/100 g, respectively; the extracted oils exhibited an iodine value of 94.14–101.15 g I/100 g oil; refractive index (40°C) was 1.465–1.466; density (25°C) was 0.902–0.903 mg/ml; saponification value was 179.01–197.25 mg KOH/g oil; and the acid value was 4.036–4.323 mg KOH/g oil. The apple seed oils mainly consisted of linoleic acid (50.7–51.4 g/100 g) and oleic acid (37.49–38.55 g/100 g). Other prominent fatty acids were palmitic acid (6.51–6.60 g/100 g), stearic acid (1.75–1.96 g/100 g) and arachidic acid (1.49-1.54 g/100 g). Apple seed oil was proven to possess interesting properties, emerging from its chemical composition and from the evaluation of its in vitro biological activities. The apple seed oil was almost completely active against bacteria, mildews were less sensitive to apple seed oil than yeasts, and the minimum inhibitory concentration (MIC) of apple seed oil ranged from 0.3 to 0.6 mg/ml. The observed biological activities showed that the oil had a good potential for use in the food industry and pharmacy.     

Underutilised legumes: potential sources for low-cost protein

Seeds of 104 leguminous species belonging to 17 genera were analysed for their protein contents. The promising ones were investigated for fibre, carbohydrate, ash, oil, fatty acids, amino acid profile and trypsin inhibitor activity (TIA). The variation of fibre contents was 4.1-8.9%, carbohydrate 18.4-49.2%, ash 1.8-7.2%, TIA 48.7-87.5 mg/g, oil 1.3-19.8% and protein 11.0-51.6%. The protein content (41-45%) in Acacia mellifera (41.6%), Albizzia lebbek (43.6%), Bauhinia triandra (42.7%), Lathyrus odoratus (42.8%), Parkinsonia aculeata (41.6%), Psophocarpus tetragonolobus (41.9%), Sesbania paludosa (41.2%) and S. sesban (43.8%) was in close proximity to soybean (42.8%), whereas Bauhinia retusa (51.6%), B. variegata (46.5%), Delonix elata (48.7%) and Gliricidia maculata (46.3%) showed higher percentages of protein than soybean. The essential amino acid composition of some of the seed proteins was reasonably well balanced (lysine up to 7.6%). The seeds of Bauhinia retusa (18.6%), B. triandra (16.5%), B. variegata (17.3%), Gliricidia maculata (16.2%), Parkia biglandulosa (18.9%) and Psophocarpus tetragonolobus (19.8%) had a good amount of oil, comparable to soybean (18-22%). The fatty acid composition of some genera/species was quite promising with high amount of unsaturated fatty acids.     

Physical and chemical properties,antioxidant activity,total phenol and mineral profile of seeds of seven different date fruit (Phoenix dactylifera L.) varieties

The physical and chemical properties of the date (Phoenix dactylifera L.) fruit seeds from seven date samples (Soukari, Soulag, Barhi, Khulas, Rozaiz, Soughi and Monaif) were evaluated. Energy values of dried and ground seeds were found between 4340 kcal/kg (Barhi cv) and 4795 kcal/kg (Rozaiz cv). Also, while crude oil content of seeds were established between 4.68% (Khulas cv) and 7.96% (Monaif cv), crude protein contents were found at the levels between 3.71% (Soulag cv) and 5.47% (Barhi cv). The antioxidant activity of seeds obtained from different date fruits changed between 78.03 (mg/ml) (Monaif cv) and 79.94 (mg/ml) (Barhi cv). In addition, the total phenol contents of seeds were found between 1.98 mg gallic acid equivalents (GAE)/100 g (Barhi cv) and 4.65 mg GAE/100 g (Soughi cv). The most abundant fatty acids of the date seed oils were oleic, lauric, myristic, palmitic and stearic acids. Ca, Mg, K and P contents of date seeds were found at the high concentrations.     

Physical and chemical analysis of Passiflora seeds and seed oil from China

The physical and chemical properties of seeds and seed oil from 'Tainung No. 1' passion fruit in China have been analyzed in order to evaluate their nutritional value. Proximate analysis shows that the seeds have a high amount of protein (10.8 +/- 0.60%) and are rich in oil (23.40 +/- 2.50%). The seeds are found to be a good source of minerals. They contain considerable amounts of sodium (2.980 +/- 0.002 mg/g), magnesium (1.540 +/- 0.001 mg/g), potassium (0.850 +/- 0.001 mg/g), and calcium (0.540 +/- 0.002 mg/g). The passion fruit seeds contain the 17 amino acids that are found naturally in plant protein (tryptophan is not analyzed). The essential amino acids account for 34% of the 17 amino acids. The amino acid score of passion fruit seeds protein is 74 and the first limiting amino acid is methionine and cystine. The oil extracted by solvent and supercritical dioxide carbon is liquid at room temperature and the color is golden-orange. The specific gravity of the oil is about 0.917. Comparing the chemical properties of the oil extracted by solvent with that by supercritical dioxide carbon, the latter may be suitable as edible oil directly, while the former will be edible after it must be refined to improve on clarity. Fatty acid composition of the seed oil indicates that the oil contains two essential fatty acids (linoleic acid and linolenic acid), but the content of linoleic acid (72.69 +/- 0.32%) is by far greater than that of linolenic acid (0.26 +/- 0.00%). The present analytical results show the passion fruit seed to be a potentially valuable non-conventional source for high-quality oil.     

Antioxidant activity of commonly consumed plant foods of India: contribution of their phenolic content

Antioxidants are important in protection against hypertension, diabetes, cardiovascular diseases and cancer. Polyphenols are potent antioxidants in plant foods, but their contribution to such protective effects is yet to be established. This study attempted to generate a database on the antioxidant activity (AOA) and phenolic content (PC) of some plant foods commonly consumed in India and to assess the contribution of the PC to their AOA. Plant foods belonging to different food groups such as cereals, legumes, oil seeds, oils, green leafy vegetables, other vegetables, spices, roots and tubers were analysed for AOA and PC. AOA was the highest in black pepper (0.43 mg food required for 50% inhibition of the coupled auto-oxidation of β-carotene and linoleic acid in a mixture in vitro) and it had the highest PC (191 mg gallic acid equivalent/100 g food). The AOA (18.4 mg) as well as the PC (not detectable) were the lowest in sunflower oil. PC in oil seeds was higher than that in the oil, which could be due to the hydrophilic nature of phenolics and suggests the need for greater use of oil seeds than oils. A significant correlation was observed between the AOA and PC of the plant foods studied in general (r=?0.465), but the coefficient of correlation and determination were high only in spices (r=?0.86 and r²=74%, respectively) and dehusked legumes (r=?0.65 and r²=42.2%, respectively). The results suggest that phenolics may contribute significantly to the AOA of some plant foods, such as spices and dehusked legumes.     

Nutritional and anti-nutritional potential of three accessions of itching bean (Mucuna pruriens (L.) DC var. pruriens): an under-utilized tribal pulse

Three accessions of the under-utilized legume itching bean (Mucuna pruriens var. pruriens) were analysed for proximate composition, mineral profiles, vitamins (niacin and ascorbic acid), fatty acid profiles, amino acid profiles of total seed protein, in vitro protein digestibility and certain anti-nutritional factors. All three accessions of M. pruriens var. pruriens contained higher amounts of crude protein and crude lipid when compared with most of the commonly consumed pulses. The fatty acid profiles revealed that the seed lipids contained a higher concentration of palmitic acid and linoleic acids. Amino acid profiles of M. pruriens var. pruriens revealed that the seed protein contained relatively higher levels of certain essential amino acids compared with the FAO/WHO requirement pattern. The investigated seeds are rich in minerals such as potassium, calcium, magnesium, phosphorus, iron and manganese. Anti nutritional substances such as total free phenolics, tannins, 3,4-dihydroxyphenylalanine, phytic acid, hydrogen cyanide, trypsin inhibitor activity, oligosaccharides and phytohaemagglutinating activity were investigated. The anti-nutritional fatty acid, behenic acid, also was detected in the present study.     

Innovative Application of Phytochemicals from Fermented Legumes and Spices/Herbs Added in Extruded Snacks

A trend related to adding legume seeds to various products has been observed. This work aimed to use fermented red bean/broad bean seeds and their hulls to produce extruded snacks with more beneficial nutritional properties and good sensory quality. Extruded snacks containing fermented ground seeds (50%) or hull (10%) of red bean/broad bean and corn grits with the addition of selected herbs/spices (0.5%) were prepared. The chemical composition, phenolic profile, antioxidant activity, and sensory quality were analysed. The results showed that the protein content ranged from 9 to 22.9 g 100 g⁻¹, phenolic compounds ranged from 3.97 to 12.80 mg 100 g⁻¹ (with the addition of herbs/spices, even up to 62.88 mg 100 g⁻¹), and antioxidant activities ranged from 4.32 to 10.23 Trolox g⁻¹ (ABTS assay), depending on the type of fermented materials. The addition of ground seeds/hull did not influence the consumer desirability, whereas the addition of selected herbs/spices, particularly lovage, increased it. The application of fermented red bean and broad bean seeds and their hulls, as part of the assumptions of the planetary diet, enabled enrichment of extruded corn products, which are often consumed by vegans and vegetarians, with nutritionally valuable ingredients.     

Amino acid and fatty acid compositions of Adenopus breviflorus benth seed

The amino acid and fatty acid contents of Adenopus breviflorus benth seed (locally called egwoli) with and without hull were determined. The results for the amino acid analysis showed that the seed is a good source of most of the essential amino acids and comparable to those of soya bean. The total essential amino acids of the whole seed amounted to 53.7% while that of the dehulled seed is 51.4%. Linoleic acid is the predominant fatty acid with values of 60.7 and 58.8% for whole and dehulled seeds oil respectively. It is observed that the total unsaturated fatty acid is about 80.1% for the whole seeds and 77.2% for the dehulled seeds.     

Response of rat pancreatic proteases to dietary proteins, their hydrolysates and soybean trypsin inhibitor

The present study was designed to determine whether the adaptation of pancreatic trypsin and chymotrypsin activities to dietary protein level can be attributed to the presence in the diet of the specific peptide bonds that are substrates for these enzymes. In addition, the effect of feeding soybean trypsin inhibitor (SBTI) was tested since this compound is known to stimulate synthesis of pancreatic proteases. For 3 weeks, rats were fed a diet containing 10, 20 or 30% protein as lactalbumin (control); lactalbumin predigested by trypsin, chymotrypsin or pancreatin; a mixture of amino acids; or lactalbumin supplemented with SBTI. At the end of the experiment, the activities of trypsin, chymotrypsin and amylase were determined in the rats' pancreatic homogenates. Trypsin and chymotrypsin activities at each protein level were exactly the same whether predigested lactalbumin or lactalbumin was fed. The 20 and 30% amino acid mixtures, however, produced a decrease in activities of both proteases. SBTI doubled the activities of both proteases at all three levels of protein. Amylase activity was maximal at 20% level of protein. It is concluded that adaptation of pancreatic proteases to dietary protein level is induced by small peptides that are digestion products of dietary protein. Induction of pancreatic trypsin or chymotrypsin therefore does not require the presence of substrate for these enzymes in the intestine. Dietary SBTI produced a considerable increase in pancreatic proteases compared to that produced by proteins or peptides. It is suggested that the increases in pancreatic proteases caused either by protein-rich diets or SBTI are mediated by two distinct mechanisms.     

Nutrient and antinutrient content of an underexploited Malawian water tuber Nymphaea Petersiana (Nyika)*

Uncooked/sun‐dried (UCSD) and boiled/freeze‐dried (BFD) flours of the Malawian water tuber Nymphaea petersiana (Nyika) were analyzed for selected nutrients and antinutrients. On a wet weight basis, the flours contained 8.1 and 8.0% crude protein; 0.8 and 1.0% crude fat; 12.0 and 13.0% dietary fiber; and 2.2 and 1.9% ash, respectively. The flours also contained 928 and 1300 μg/g of calcium; 2600 and 2200 μg/g of phosphorus; 88 and 20 μg/g of iron; and 22 and 20 μg/g of zinc, respectively. USCD and BFD flours were limiting in lysine and had amino acid scores of 91 and 84. The predominant fatty acids in the tubers were oleic (47%), linoleic (32%), palmitic (21%), and linolenic (7%). Tannin content was 1.5 and 1.0%; phytate content was 5.4 and 3.9 μg/g; trypsin activity was reduced from 400 to 55 TIU/g of tuber and chymotrypsin activity was reduced from 240 to 50 CIU/g by moist heat. Hydrogen cyanide levels were below detection limits (LOD < 16 nmoles/L) for both UCSD and BFD flour samples.     

Effect of soy protein, casein and trypsin inhibitor on cholesterol, bile acids and pancreatic enzymes in mice

Dietary vegetable proteins may lower plasma cholesterol compared to animal proteins. We considered the possibility that lower digestibility and the trypsin inhibitor (TI) content of plant proteins could lead to alterations in bile acid metabolism and exocrine pancreatic function mediating some of this change. Mice were fed cholesterolemic diets of different protein source and TI content: casein, soy protein isolate, or casein plus TI for 4 weeks. Plasma and liver cholesterol were measured; pancreata, intestinal contents and mucosal scrapes were collected for bile acid, trypsin, chymotrypsin, amylase, and lipase assays. The soy group had lower plasma cholesterol levels. Intestinal bile acids in this group were higher, suggesting a causal relationship (increased bile acid secretion leading to increased cholesterol catabolism). Conversely, liver cholesterol in this group was raised, reflecting a possible shift in body cholesterol pools. TI addition did not affect lipid metabolism, though it did affect pancreatic function: it led to increased pancreatic weight and depressed intestinal trypsin activity, but elevated chymotrypsin and amylase levels in pancreas and intestine and increased trypsin levels in the pancreas. Therefore, soybean TI does not seem to affect cholesterol metabolism, though it greatly affects pancreatic secretion. On the other hand, soy protein has a marked effect on the bile acid and cholesterol metabolism, which may be a function of protein quality.     

Physical and chemical analysis of Passiflora seeds and seed oil from China

The physical and chemical properties of seeds and seed oil from ‘Tainung No. 1’ passion fruit in China have been analyzed in order to evaluate their nutritional value. Proximate analysis shows that the seeds have a high amount of protein (10.8±0.60%) and are rich in oil (23.40±2.50%). The seeds are found to be a good source of minerals. They contain considerable amounts of sodium (2.980±0.002 mg/g), magnesium (1.540±0.001 mg/g), potassium (0.850±0.001 mg/g), and calcium (0.540±0.002 mg/g). The passion fruit seeds contain the 17 amino acids that are found naturally in plant protein (tryptophan is not analyzed). The essential amino acids account for 34% of the 17 amino acids. The amino acid score of passion fruit seeds protein is 74 and the first limiting amino acid is methionine and cystine. The oil extracted by solvent and supercritical dioxide carbon is liquid at room temperature and the color is golden–orange. The specific gravity of the oil is about 0.917. Comparing the chemical properties of the oil extracted by solvent with that by supercritical dioxide carbon, the latter may be suitable as edible oil directly, while the former will be edible after it must be refined to improve on clarity. Fatty acid composition of the seed oil indicates that the oil contains two essential fatty acids (linoleic acid and linolenic acid), but the content of linoleic acid (72.69±0.32%) is by far greater than that of linolenic acid (0.26±0.00%). The present analytical results show the passion fruit seed to be a potentially valuable non-conventional source for high-quality oil.     

Allergenicity,trypsin inhibitor activity and nutritive quality of enzymatically modified soy proteins

Two ultrafiltered soy flour protein fractions were evaluated; the first was obtained by hydrolysis (0.5–3 kDa, F_0.5–3), and the second was an enzymatically methionine-enriched fraction (1–10 kDa, F_1–10E). Amino acid profiles, protein quality, allergenicity (against soy-sensitive infant sera) and trypsin inhibitor activity were determined. Fraction F_1–10E fulfilled amino acid requirements for infants, whereas the F_0.5–3 fraction was methionine deficient. Both fractions were similar in net protein utilization, and F_1–10E digestibility was comparable with casein and higher (P?<?0.05) than F_0.5–3 or soy isolate. Allergenicity of SF was reduced to 21.5% with the hydrolysis in F_1–10E and it was not detected in F_0.5–3. Residual trypsin inhibitor activity with respect to soy flour was 8.1%, 3.3% and 1% for hydrolysate, F_1–10E and F_0.5–3, respectively. Both fractions presented high nutritive quality and reduced or null allergenicity. The trypsin inhibitor activity decreased along processing and could be a useful indicator for production of hypoallergenic proteins.     

Protease inhibitor content of human dietary samples

A large body of experimental work has revealed that protease inhibitors (PI) are highly effective suppressors of carcinogenesis. Little is known about the level of PI activity in the diet of the US population. In the present study, we assayed the levels of PI activity in dietary samples from 31 free-living subjects who saved duplicate portions of all foods consumed over two 24-hour periods, six months apart. The majority of samples (90%) contained detectable PI activity; 82% contained trypsin inhibitory activity; 61% contained chymotrypsin inhibitory activity. Of those samples containing chymotrypsin inhibitory activity, 87% also contained trypsin inhibitory activity. The median concentration of soluble chymotrypsin inhibitory activity present in these samples was 6.5 micrograms/g food (range 0-150 micrograms/g food), whereas the median concentration of soluble trypsin inhibitory activity was 14.5 micrograms/g food (range 0-465 micrograms/g food). We conclude that a) human diet samples contain both chymotrypsin and trypsin inhibitory activity, b) the levels of PI in some of these samples was similar to that found to be anticarcinogenic in animal studies, and c) due to the large within-subject variation in PI intake, assessment of long-term dietary intake in epidemiological studies will be necessary to accurately classify subjects according to PI intake.     

The phenolic compounds,tocopherols, and phytosterols in the edible oil of guava (Psidium guava) seeds obtained by supercritical CO2 extraction

An edible oil was obtained from guava seeds by supercritical CO₂ extraction. The oil was characterized by its fatty acid composition, physicochemical properties, and the contents of phenolic, miscellaneous, phytosterol, and tocopherol compounds. The oil, obtained with a yield of 8.6 ± 1.2 g oil/100 g guava seeds, had a high content of linoleic acid (78.5 %, w/w), followed by that of oleic acid (13.8 %, w/w). The guava seed oil had physicochemical properties comparable to those published in previous research, except for the low stability to oxidation. The chromatographic profile of the phenolic and miscellaneous compounds was dominated by vanillin (9.6 ± 0.3 mg/100 g oil) and cinnamaldehyde (9.4 ± 0.2 mg/100 g oil), followed by vanillic acid (3.9 ± 0.4 mg/100 g oil), cinnamic acid (2.4 ± 0.1 mg/100 g oil), and minor amounts of other phenolic aldehydes. Among the phytosterols and tocopherols, β-sitosterol (1048.9 ± 48.4 mg/100 g oil) and γ-tocopherol (82.6 ± 3.7 mg/100 g oil) were the most abundant. The low oxidative stability of the oil compared to that published in previous reports might reflect the high complexity of this matrix. This oil might have applications, directly or after blending with more stable edible oils.