• Food Engineering Progress
• /
• v.15 no.1
• /
• pp.41-47
• /
• 2011

The defatted rice bran (DRB) was enzymatically hydrolyzed using eight commercial proteases for 4hr at optimum pH and temperature. Proteolytic hydrolysates were examined in supernatant and precipitate using lowry, semimicro kjeldahl and gravimetric method using weight difference before and after enzymatic hydrolysis. In lowry and kjeldahl protein assay method, two proteases (Alcalase and Protease N) were found to be the most effective enzymes. In gravimetric method, 60.6~118.3 mg protein/g DRB was hydrolyzed after eight commercial proteases treatments. Similar to lowry and kjeldahl method, 118.3 and 107.1 mg protein/g DRB were hydrolyzed after Alcalase and Protease N treatments, respectively. When two or three effective proteases (Protamex, Alcalase and Protease N) were applied at one time to obtain synergistic effect, significant increase (P<0.05) was observed when three proteases were applied at one time (63.4 mg protein/g DRB in lowry method and 204.5 mg protein/g DRB in gravimetric method). This result suggests that Alcalase and Protease N were the most effective enzymes for proteolysis of DRB and three commercial enzymes (Protamex, Alcalase and Protease N) showed the synergistic effect on the hydrolysis of DRB.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.309-315
• /
• 2011

Rice syrup meal (RSM) was enzymatically hydrolyzed using eight commercial proteases (Protamex, Neutrase, Flavourzyme, Alcalase, Protease M, Protease N, Protease A, Molsin F) for 4 hr at optimum pH and temperature. Proteolytic hydrolysates were examined in supernatant and precipitate using Lowry protein assay, semimicro Kjeldahl method and gravimetric method using weight difference before and after enzymatic hydrolysis. Although RSM contains a high amount of protein (71.2%), only a very small amount of protein was hydrolyzed. Two proteases (Protease M and Protease N) were found to be the most effective in the hydrolysis of RSM protein. In Lowry method, 57.5 and 59.0 mg protein/g RSM were hydrolyzed after Protease M and Protease N treatments, respectively. In gravimetric method, 80.0 and 85.4 mg protein/g RSM were hydrolyzed after Protease M and Protease N treatments. In Kjeldahl method, 67.43 and 70.43 mg protein/g RSM were hydrolyzed after Protamex and Protease N treatments, respectively. For synergistic effect, two or three effective commercial proteases (Protease M, Protease N and Protease A) were applied to RSM at one time. The highest hydrolysis of RSM protein was observed in both Lowry protein assay (80.3 mg protein/g RSM) and gravimetric methods (153.2 mg protein/g RSM) when three commercial proteases were applied at one time, suggesting the synergistic effect of those proteases.

• Journal of Nutrition and Health
• /
• v.36 no.9
• /
• pp.942-949
• /
• 2003

This study was longitudinally conducted to evaluate the intakes of protein, Ca, Mg and P of exclusively breast-fed infants compared with the Recommended Dietary Allowances (RDA) for Korean infants. Twenty Korean lactating women and their infants during the first 3 months of lactation in Incheon area were participated. Protein, Ca and Mg, and P contents in the milk were determined using semimicro Kjeldahl (N ${\times}$ 6.38) , atomic absorption spectrophotometer and colorimeter, respectively, and also the milk consumption of the infants was measured by the test-weighing method. Protein contents of the milk were 1.96, 1.63, 1.51, 1.25 and 1.16 g/100 ml, and protein intakes of the breast-fed infants were 9.00, 9.85, 9.17, 8.97 and 7.76 g/day at 7, 15, 30, 60 and 90 days postpartum. The average protein intake per body weight of the breast-fed infants was 1.84 g/kg/day. The average intakes of Ca, Mg, P were 172.1 mg/day, 15.2 mg/day and 91.4 mg/day, respectively, and the average Ca/P ratio was 1.91. There was positive correlation between protein and Ca, protein and p, and Ca and P contents while negative correlation between Mg and P, The body weight of breast-fed infants increased normally from 3.6 $\pm$ 0.41 g at birth to three month during lactation. It is suggested that the breast-fed infants in Incheon area consume almost adequately protein, Ca and P from the milk compared with RDA for Korean infants.

• Journal of Nutrition and Health
• /
• v.35 no.7
• /
• pp.771-778
• /
• 2002

The purpose of this study is to investigate the contents of protein, fat, lactose and energy in the human milk and the intake of human milk and those nutrients in breast-fed infants from 16 lactating women in Seoul area during the first 5 months postpartum. Daily human milk intake was determined by test-weighing method and the milk from 16 mothers was analyzed for protein (semimicro Kjeldahl, N $\times$ 6.38), fat (milk checker), lactose (HPLC). Energy was calculated by Atwater and milk factor. The mean intake of human milk to the 5th month of lactation was 668 $\pm$ 186 $m\ell$/day. Mean protein contents of the human milk at 0.5, 12, 3, 4 and 5 months postpartum showed 1.48, 1.35, 1.17, 1.11, 1.15 and 1.10 g/100 $m\ell$ respectively. Lipid and lactose contents of the human milk during the first S months postpartum averaged 3.38 g/100 $m\ell$ and 6.79 g/100 $m\ell$. Energy contents at 0.5, 12, 3, 4 and 5 months postpartum showed 64.2, 66.1, 68.3, 60.1, 58.9 and 61.2 g/100 $m\ell$ respectively. Protein intake of infants from the human milk was 8.22 g/day which was 54.8% of Korean RDA. Lipid and lactose intake of infants were 23.0 and 45.6 g/day. Energy intake of infants was 422.3 kcal/day which was 84.4% of Korean RDA. Total energy content was almost same value regardless of Atwater or milk factor but the energy ratio was some different. Protein and solid contents decreased the course of lactation but lactose content was less changed. These results suggest that more research were required for the RDA.

• Korean journal of food and cookery science
• /
• v.15 no.5
• /
• pp.483-489
• /
• 1999

In order to study effects of herbs on the changes of the taste compounds, color and sensory evaluation of soup stock. The crude protein, free amino acids and nucleotide contents in brisket soup stock were investigated by use of semimicro-kjeldahl method and HPLC. In addition, color measurement and sensory evaluation were investigated. Generally, The crude protein, free amino acids and nucleotides contents in various soup stocks increased by heating time. The crude protein contents in the Go, Ca and A soup stocks increased much more than control soup stock. The free amino acids were the highest content in the Go$\_$5/ soup stock specially, arginine, alanine, glycine, threonine and glutamic acid. The free amino acid contents were lower in C$\_$5/ and O$\_$5/ soup stock than B$\_$5/ soup stock. 5'-IMP, inosine and hypoxanthine concentration in Go$\_$5/(33.4 mg%) soup stock showed highest value. But those in the C$\_$5/(5.8 mg%) and O/sun 5/(5.7 mg%) soup stocks were lower than that in the B$\_$5/ soup stock. From a sensory evaluation, the all of sensory score of samples was not significantly difference.