Go-Eun Hong

Production of the isoflavone aglycone and antioxidant activities in black soymilk using fermentation with Streptococcus thermophilus S10

The best starter culture for fermented black soymilk was determined. Black soymilk was fermented using Lactobacillus acidophilus ATCC 4356 (LA), Lactobacillus plantarum P8 (LP), and Streptococcus thermophilus S10 (ST). An ST single culture exhibited higher β-glucosidase activities than LAST (LA:ST=1:1, v/v), LPST (LP:ST=1:1, v/v), and LALPST (LA:LP:ST=1:1:1, v/v) mixed cultures. The pH of fermented black soymilk was significantly (p<0.05) decreased during fermentation due to an increase in lactic acid formed by lactic acid bacteria. The β-glucosidase activity of the ST single culture was significantly (p<0.05) higher than for mixed cultures. Black soymilk fermented with ST alone showed significantly (p<0.05) more bioconversion of the isoflavone glycoside to aglycone, compared with controls. Black soymilk fermented with ST resulted in the best antioxidant effect. The ST single culture was best for production of health functional fermented black soymilk.

In vivo protective effects of dietary curcumin and capsaicin against alcohol-induced oxidative stress

BALB/c mice were exposed to chronic alcohol-induced oxidative stress by intragastric administration of excessive ethanol (5 g/kg body weight) during the 24-week period. Curcumin (0.016%) or capsaicin (0.014%) containing diets were fed with or without ethanol treatment in four groups. There was no statistically significant difference in the behavioral test between all groups during the experimental period. Only one alcohol-treated mouse fed a normal diet showed a behavioral disorder and died before the raising period was completed. There were no effects on the activity of catalase and superoxide dismutase in the brain. However, curcumin or capsaicin treatment prevented alcohol-induced decline in brain weight. Furthermore, the levels of malondialdehyde and phosphatidylcholine hydroperoxide were significantly reduced in the brain tissue extract. The findings of this study demonstrated and confirmed the antioxidant effect of curcumin and capsaicin against alcohol-induced oxidative stress, and they suggest a direction for further studies.

Effect of Addition of Allium hookeri on the Quality of Fermented Sausage with Meat from Sulfur Fed Pigs during Ripening.

The effect of the addition of Allium hookeri on the quality of fermented sausage made with meat from sulfur fed pigs was examined, throughout a 60 d ripening period. There were two treatments in animal management: normal feed fed pigs, and sulfur fed pigs given 0.3% sulfur mixed normal feed. Fermented sausage manufactured with meat from normal feed fed pigs, and with meat from sulfur fed pigs, and 1% A. hookeri-containing fermented sausage processed with meat from sulfur fed pigs, were determined at 1 d, 15 d, 30 d, and 60 d. The meat qualities in fermented sausage were measured by DPPH radical scavenging activity (DPPH), ABTS+ radical scavenging activity (ABTS+), total phenolic acids, and total flavonoid contents. Fermented sausage made from pigs that had been fed with 0.3% sulfur was protected from oxidation by reduced free radical, as shown by the significant increase in DPPH and ABTS+ values, compared with fermented sausage made from normal feed fed pigs (p<0.05). A. hookeri-added fermented sausage with sulfur fed pork was shown to increase the values in DPPH, ABTS+, total phenolic acid, and total flavonoid contents, by comparison with both the control sausage, and sausage with sulfur fed pork, at 60 d. These results suggest that A. hookeri in meat from sulfur fed pigs could be a source of natural addition, to increase quality in the food industry.

Effect of Dietary Supplementation with Processed Sulfur on Meat Quality and Oxidative Stability in Longissimus dorsi of Pigs

The effects of dietary supplementation of processed sulfur in pigs according to the level provided during the fattening phase were examined. The pigs were divided into three groups: control (CON), non-sulfur fed pigs; T1, 0.1% processed sulfur fed pigs; T2, 0.3% processed sulfur fed pigs. Physicochemical and sensory properties, as well as meat quality and oxidative stability of the Longissimus dorsi muscle were investigated. The feeding of processed sulfur did not affect moisture and protein contents (p>0.05). However, the crude fat content of T2 was significantly decreased compared to CON (p<0.05), while the pH value of T2 was significantly higher than those of both CON and T1 (p<0.05). Cooking loss and expressible drip of T2 were also significantly lower than that of CON (p<0.05). The redness of meat from T1 was significantly higher than both CON and T2 (p<0.01). During storage, lipid oxidation of the meat from sulfur fed pigs (T1 and T2) was inhibited compared to CON. Examination of omega-3 polyunsaturated fatty acids revealed T2 to have significantly higher content than CON (p<0.05). In the sensory test, the juiciness and overall acceptability of T2 recorded higher scores than CON. This study demonstrated that meat from 0.3% processed sulfur fed pigs had improved nutrition and quality, with extended shelf-life.

Enhancement of physicochemical, microbiological and sensory properties of dry-cured loin by using processed sulfur-fed pigs

The present study showed that processed sulfur supplementation and processing condition affected changes in physicochemical, microbial and sensory properties of dry-cured loin. The pigs were divided into two groups at the fattening phase: non-sulfur-fed pigs (NSFP) and 0.3% processed sulfur-fed pigs (SFP) in fattening phase. The crude fat content of SFP was lower than that of NSFP in raw meat and dry-cured loin. Lipid and pigment oxidation were suppressed in SFP compared with NSFP during whole process. Lightness of SFP was significantly higher than that of NSFP during storage. SFP showed higher colour stability than did NSFP during storage. Moreover, microbial spoilage of dry-cured loin was greatly prevented in SFP compared with NSFP. Free amino acids related to taste in SFP were significantly higher than those in NSFP. Polyunsaturated fatty acid of dry-cured loin from SFP group was higher than that of NSFP, while saturated fatty acid of NSFP was significantly higher than that of SFP. SFP had higher preference and flavour scores than did NSFP in a sensory test. Feeding processed sulfur improved the meat-quality characteristics and extended the shelf-life of meat products.

Biodegradation of Capsaicin by Bacillus licheniformis SK1230

Capsaicin is a major representative component in pepper and it has gained interest by its health beneficial effects. An enzymatic hydrolysate of capsaicin has also been of great interest, because it can be applied to the reduction pungency of pepper or production of natural flavor. We first developed a simple screening method to isolate capsaicin-degrading bacteria showing a clear zone. A cloudy solid medium was prepared by the addition of capsaicin as sole carbon and nitrogen sources to 3-(Nmorpholino) propanesulfonic acid (MOPS) minimal medium, and the bacteria showing clear zone around the colony was isolated from Korean traditional pickled pepper. The isolated strain was identified as Bacillus licheniformis using 16S rRNA gene sequence analysis. B. licheniformis SK1230 was able to utilize capsaicin for both of carbon and nitrogen sources for its growth. The hydrolysis of capsaicin by B. licheniformis was verified using high-performance liquid chromatography, and capsaicin in medium was depleted depending on culture time. Capsaicin hydrolysate was composed of vanillylamine and capsiate (8-methyl-6-trans-nonenoic acid).

Effects of fermented black soybean pulp on lipid and bone metabolism in ovariectomized rats

To investigate the effect of fermented black soybean pulp on serum lipid metabolism and osteoporosis in ovariectomized rats, Sprague-Dawley rats were divided into 4 groups: sham-operated control group, ovariectomized control group, ovariectomized group treated with black soybean pulp (BSP), and ovariectomized group treated with fermented black soybean pulp (FBSP). Rats were fed experimental diets for 8 weeks after ovariectomy. Compared to the control, FBSP supplemen-tation led to the improving effect for femur weight, abdominal fat, alanine aminotransferase, aspartate aminotransferase activity, hepatic lipid levels, and thiobarbituric acid reactive substances. Also, serum HDL-cholesterol, estradiol levels, serum alkaline phosphatase activity, and osteocalcin levels in the FBSP group were significantly lower than in the control group (p<0.05). These results suggest that FBSP is effective in improving lipid metabolism and preventing osteoporosis in ovariectomized rats.

Effects of Whey Powder Supplementation on Dry-Aged Meat Quality

The objective of this study was to determine the effect of dietary supplementation with whey powder (WP, 1g/kg feed) from weaning to slaughter (150 d) on dry-aged loin quality of pigs. Fifty-eight pigs were randomly divided into two dietary treatment groups (seven replications of four pigs per treatments). Basal diet with 0.1% whey powder was supplied to the WP group. Basal diet was used for the control group (CON). Diet whey protein did not appear to influence the moisture or protein contents. However, ash and fat contents were significantly (p<0.05) decreased in the WP group compared to the control group. Drip loss was significantly (p<0.05) lower in the WP group than that of the control group. Increasing redness with decreasing lightness was found in the inner loin of the WP group. Calcium and iron contents in the WP group were significantly higher than those in the control group. Protein degradation was higher in the WP group than that in the control group (p<0.05), whereas shear force was lower in the WP group than that in the control group (p<0.05). In conclusion, the basal diet supplemented with 0.1% whey powder influence negatively the lipid oxidation of meat whereas the texture property and mineral composition of meat from whey powder fed pigs are developed.

Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage

Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (p<0.05). The percentage of myoglobin denaturation (PMD) of the CA groups was also increased according to the level of CA during storage. Total aerobic counts, Enterobacteriaceae counts, volatile basic nitrogen and thiobarbituric acid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (p<0.05). The findings indicated positive effects in the physicochemical properties and storage ability of sous vide chicken breast at 2% and 5% citric acid concentrations.

Effect of Allium hookeri and whey powder in diet of pigs on physicochemical characteristics and oxidative stability of pork

Abstract The objective of this study was to determine the effect of Allium hookeri supplementation with whey powder in pig diet on meat quality, oxidative stability and sensory characteristics of Longissimus dorsi muscle samples. A total of 60 pigs were randomly assigned into the following three groups (four replicate pens per group with five pigs per pen): CON group, basal diet; AH, dietary supplementation with 10 g A. hookeri/kg feed and AHW, dietary supplementation with 5 g A. hookeri/40 g whey powder/kg feed. Proximate composition of muscle sample was not significantly affected by A. hookeri supplementation. On average, the AHW group showed higher pH but less cooking loss than the CON group. However, the AH and AHW groups had lower (p < .05) collagen content and shear force than the CON group. Retardation of lipid oxidation was significantly higher in the AH compared to that in the CON group. However, fatty acid compositions were not significantly affected by A. hookeri or whey powder supplementation, the exceptions were the C18:0 and C18:3n − 3 that showed the highest and the C20:3n − 3 the lowest proportions in the AH group. The AH group exhibited higher free amino acid contents such as Glu, Asn, Thr, Arg, Tyr, Ile and Leu than the AHW or CON group. However, sensory characteristics were not significantly affected by supplementation with A. hookeri or whey powder. These findings demonstrate that A. hookeri might be a promising supplement for pigs diet to improve meat oxidative stability without negatively compromise the nutritional properties and sensory quality.