Protein Digestibility of Selected Legumes Treated with Ultrasound and High Hydrostatic Pressure During Soaking

In vitro protein digestibility (IVPD) of lentils, chickpeas, peas, and soybeans treated with ultrasound or high hydrostatic pressure (HHP) during soaking and then heated for 30 min at 98°C was determined using the three-enzyme method (trypsin, chymotrypsin, and peptidase). The IVPD of raw legumes ranged from 72% for soybeans to 83% for dry green peas. The increase in the IVPD after soaking was observed in lentils but not in other legumes. Heating increased the IVPD of the tested legumes by 2–13%. While the effects of applying ultrasound or HHP on IVPD of legumes were mostly inconsistent or insignificant, soaking under HHP for 1 hr and subsequent heating at 98°C for 30 min increased IVPD of legumes. Compared with raw legumes, the soluble protein concentrates exhibited 2–4% higher IVPD, while insoluble proteins exhibited 0.2–1.5% lower IVPD. SDS-PAGE of legume proteins before enzyme digestion exhibited 8–18 protein bands from 20 kDa to 100 kDa representing isolated soluble proteins and from 20 kDa to 100 kDa representing insoluble proteins. After enzyme digestion, soluble proteins exhibited 2–6 minor protein bands with molecular weights <30 kDa, while insoluble proteins of lentils, chickpeas, and peas exhibited one major protein band at ≈52 kDa and two or three minor protein bands with molecular weights <30 kDa. The major insoluble proteins observed as electrophoresis bands after enzyme digestion may be responsible for the reduced protein digestibility of legume proteins.     

Generation and evaluation of reassortant influenza vaccines made by reverse genetics for H9N2 avian influenza in Korea

The prevalence and continuous evolution of H9N2 avian influenza viruses in poultry have necessitated the use of vaccines in veterinary medicine. Because of the inadequate growth properties of some strains, additional steps are needed for producing vaccine seed virus. In this study, we generated three H9N2/PR8 reassortant viruses using a total cDNA plasmid-transfection system, as an alternative strategy for developing an avian influenza vaccine for animals. We investigated the vaccine potency of the reassortant viruses compared with the existing vaccine strain which was adapted by the 20th serial passages in embryonated eggs with A/Ck/Kor/01310/01 (H9N2). The H9N2/PR8 reassortant viruses, containing the internal genes of the high-yielding PR8 strain and the surface gene of the A/Ck/Kor/01310/01 strain, could be propagated in eggs to the same extent as existing vaccine strain without additional processing. Similar to vaccine strain, the H9N2/PR8 reassortant viruses induced hemagglutination-inhibiting antibodies in chickens and prevented virus shedding and replication in multiple organs in response to homologous infection. However, due to the continuing evolution and increasing biologic diversity of H9N2 influenza in Korea, the vaccine provided only partial protection against currently isolates. Taken together, our results suggest that the H9N2/PR8 reassortant virus can be used as a seed virus for avian influenza vaccines in poultry farm. Considering the constant genetic changes in H9 strains isolated in Korea, this reverse genetic system may offer a prompt and simple way to change the vaccine seed virus and mitigate the impact of unexpected influenza outbreaks.     

Synthesis of hydrophilic copolyesters and the characterization of their moisture-related cooling properties

A series of copolyesters (Co-PETs) containing poly(ethylene glycol) (PEG), 5-sodiumsulfodimethyl isophthalate (DMS), and dimethyl isophthalate (DMI) were synthesized via the conventional two-step melt-polycondensation method. The synthesized Co-PETs were characterized by ¹H-NMR spectroscopy, FT-IR spectroscopy, differential scanning calorimeter (DSC), and thermogravimetric analyzer (TGA). The DSC results showed that the melting temperature (T _m) and the heats of fusion (ΔH _m) of Co-PETs decreased with increasing the DMS content in Co-PET, while the inclusion of PEG did not affect their thermal properties significantly. The water absorption and the water contact angle of the Co-PET films were found to be significantly affected by the DMS content rather than PEG content. The moisture-related cooling properties of the fabric samples made of Co-PET 5 as well as PET were evaluated by using liquid moisture management tester (MMT) and Q _max measurements. The MMT and Q _max results indicated that Co-PET 5 fabric containing DMS 1.0 mol% and PEG 10.0 wt% in Co-PET seemed to be a good candidate for the fabric having durable cooling effects.     

Retardation of Discoloration in Barley Flour Gel and Dough

Dark discoloration negatively influences the aesthetic properties of barley‐based food products. The effects of abrasion and heat treatment of grains, exclusion of oxygen, and the use of antibrowning agents on the retardation of darkening in barley flour gel or dough were determined in four types of barley, including hulled proanthocyanidin‐containing and hulled proanthocyanidin‐free, hulless regular, and hulless waxy barley. Abrasion by >30% in hulled barley and by >15% in hulless barley significantly increased the brightness (L*) of barley flour dough by 0.1–7.1. Steam heating of abraded grains also significantly increased the L* of barley flour gels by 1.8–3.4. Ascorbic acid at 1,500 ppm was most effective for retarding discoloration of barley flour dough, followed by 50 ppm of 4‐hexylresorcinol, which is an enzyme competitive inhibitor. The discoloration of barley flour dough was also effectively reduced by storing the dough sheets at 4°C under nitrogen gas to exclude oxygen or under anaerobic conditions at 20°C. Discoloration of barley‐based food products may be effectively controlled by selecting genotypes with low discoloration development such as proanthocyanidin‐free genotypes, by lowering total polyphenol content or polyphenol oxidase (PPO) activity through abrasion, by heat treatment, by exclusion of oxygen, and by the use of enzyme inhibitors.     

Angiotensin Converting Enzyme in Bovine Ovarian Follicular Fluid and its Relationship with Oestradiol and Progesterone

The purpose of the present study was to identify angiotensin converting enzyme (ACE) in bovine ovarian follicular fluid and to relate the ACE activity to the phase of the oestrous cycle, pregnancy, and the follicular fluid concentrations of oestradiol and progesterone. The ACE activity was similar to that found in bovine serum and was completely inhibited by the specific ACE inhibitor captopril. The 50% inhibitory concentration (IC₅₀) was 1.4 × 10^?8 mol/l (range 0.8 × 10^?8 to 5.0 × 10^?8 mol/l; n=6), which is similar to that found in bovine and human serum. The ACE activity did not differ in the pre‐ovulatory and luteal phase, pregnancy or cystic follicles. It correlated with the follicular fluid concentration of progesterone in cycling cows (ρ=0.476; p < 0.005; n=36), but did not correlate with the diameter of the follicles, the follicular fluid concentration of oestradiol or the ratio between the oestradiol and progesterone concentrations. The demonstration of ACE in bovine ovarian follicular fluid provides further evidence for the presence of a local renin–angiotensin system in the bovine ovary.     

Genotypic Variation in Nutritional Composition of Buckwheat Groats and Husks

Buckwheat (Fagopyrum esculentum), a highly nutritious pseudocereal rich in bioactive compounds, is principally cultivated in central and eastern European countries. Buckwheat groats and husks of 10 cultivars were subjected to nutritional composition analysis and in vitro starch digestibility determination. Significant genetic variation was detected in buckwheat groats for 1,000‐kernel weight (16.5–39.8 g), protein content (10.2–17.9%), soluble dietary fiber (1.4–3.4%), insoluble dietary fiber (2.3–8.6%), total dietary fiber (3.6–10.6%), free phenolics (4.5–17.1 mg of gallic acid equivalent [GA]/g), and total phenolics content (6.8–20.7 mg of GA/g). The buckwheat husks exhibited large differences between cultivars in protein content (3.0–6.5%), bound phenolics (6.7–26.1 mg of GA/g), and total phenolics content (32.4–58.6 mg of GA/g), which was 1.5–8 times higher than in the groat. Cooked and cooled buckwheat groats exhibited lower starch digestibility and greater resistant starch content than raw buckwheat groats. Buckwheat cultivars with unique nutritional composition, such as Co901 and Ta‐1, were identified for future breeding.     

Severe dietary lysine restriction affects growth and body composition and hepatic gene expression for nitrogen metabolism in growing rats

Dietary lysine restriction may differentially affect body growth and lipid and nitrogen metabolism, depending on the degree of lysine restriction. This study was conducted to examine the effect of dietary lysine restriction on growth and lipid and nitrogen metabolism with two different degree of lysine restriction. Isocaloric amino acid–defined diets containing 1.4% lysine (adequate), 0.70% lysine (50% moderate lysine restriction) and 0.35% lysine (75% severe lysine restriction) were fed from the age of 52 to 77 days for 25 days in male Sprague–Dawley rats. The 75% severe lysine restriction increased (p < 0.05) food intake, but retarded (p < 0.05) growth, increased (p < 0.05) liver and muscle lipid contents and abdominal fat accumulation, increased (p < 0.05) blood urea nitrogen levels and mRNA levels of the serine‐synthesizing 3‐phosphoglycerate dehydrogenase gene, but decreased (p < 0.05) urea cycle arginase gene mRNA levels. In contrast, the 50% lysine restriction did not significantly (p > 0.05) affect body growth and lipid and nitrogen metabolism. Our results demonstrate that severe 75% lysine restriction has detrimental effects on body growth and deregulate lipid and nitrogen metabolism.