• Food Science of Animal Resources
• /
• v.43 no.2
• /
• pp.305-318
• /
• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.4
• /
• pp.512-519
• /
• 2023

Pacific oysters Crassostrea gigas are a popular shellfish in the Republic of Korea. However, due to their abundant moisture and nutrient content, oysters are susceptible to microbiological growth and biochemical changes, which lead to quality degradation. Therefore, the present study aimed to investigate the effectiveness of modified atmosphere packaging (MAP) in maintaining the quality of raw oysters during storage. Microbiological and physicochemical parameters such as pH, glycogen content, soluble protein, turbidity, and volatile basic nitrogen (VBN) were analyzed for oysters stored under various gas compositions and storage periods. The results showed that there was no significant increase in viable cell count in MAP oysters after six days in MAP oysters. Moreover, the physicochemical quality of non-MAP oysters deteriorated rapidly, whereas the quality of MAP oysters were maintained during storage. This study suggests that MAP can be an effective technique for maintaining the freshness of raw oysters during distribution and storage, and may also be useful for extending the shelf-life and maintaining the quality of other seafood products.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.214-214
• /
• 2022

Soluble starch synthases (SSs) elongate α-glucans from ADP-Glc to the glucan nonreducing ends and play a critical role in synthesizing resistant starch in the rice. A total of 10 SSs isoforms were reported in rice, including granules-bound starch synthase I (GBSSI), GBSSII, starch synthase I (SSI), SSIIa (SSII-3), SSIIb (SSII-2), SSIIc (SSII-1), SSIIIa (SSIII-2), SSIIIb (SSIII-1), SSIVa (SSIV-1), and SSIVb (SSIV-2). SSIII proteins are involved in forming the B chain and elongating cluster filling chains in amylopectin metabolism. The functions of SSIIIb (SSIII-1) are less clear as compared to SSs. Here, we sought to shed light on the genetic diversity profiling of the SSIII-1 gene in 374 rice accessions composed of 54 wild-type accessions and 320 bred cultivars (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture). In total, 17 haplotypes were identified in the SSIII-1 coding region of 320 bred cultivars, while 44 haplotypes were detected from 54 wild-type accessions. The genetic diversity indices revealed the most negative Tajima's D value in the temperate-japonica, followed by the wild type, while Tajima's D values in other ecotypes were positive, indicating balancing selection. Nucleotide diversity in the SSIII-1 region was highest in the wild group (0.0047) while lowest in temperate-japonica. Lower nucleotide diversity in the temperate-japonica is evidenced by the negative Tajima's D and suggested purifying selection. The fixation index (F_ST) revealed a very high level of gene flow (low F_ST) between the tropical-japonica and admixture groups (F_ST=-0.21) followed by admixture and wild groups (-0.04), indica and admixture groups (0.02), while low gene flow with higher F_ST estimates between the temperate-japonica and aus groups (0.72), tropical-japonica and aromatic groups (0.71), and temperate-japonica and admixture groups (0.52). Taken together, our study offers insights into haplotype diversity and evolutionary fingerprints of SSIII-1. It provides genomic information to increase the resistant starch content of cooked rice.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.212-212
• /
• 2022

Soluble starch synthase (SS) IV-2 is one of the starch synthase gene family members and responsible for starch chain elongation interacting with other rice eating and cooking quality controlling genes (e.g., AGPlar and PUL). SSIV-2 is mainly expressed in leaves, especially at grain-filling stage and its alleles can significantly affect rice quality. Here, we investigated the genetic diversity and population structure analyses of SSIV-2 gene by using 374 rice accessions. This rice set was grouped into 320 cultivated bred (subsequently classified into temperate japonica, indica, tropical japonica, aus, aromatic and admixture) and 54 wild rice. Haplotyping of cultivated rice accessions provided a total of 7 haplotypes, and only three haplotypes are functional indicating four substituted SNPs in two exons of chromosome 5: T/A and G/T in exon 4, and C/G and G/A in exon 13. Including the wild, a highest diverse group (0.0041), nucleotide diversity analysis showed temperate japonica (0.0001) had a lowest diversity value indicating the origin information of this gene evolution. Higher and positive Tajima5s D value of indica (1.9755) indicate a selective signature under balancing selection while temperate japonica (-0.9018) was in lowest Tajima's D value due to a recent selective sweep by positive selection. We found the most diverse genetic components of the wild in PCA but shared in some portion with other cultivated groups. Fixation index (F_ST-values) and phylogenetic analysis indicate a closer relationship of the wild with indica (F_ST=0.256) than to its association to both of temperate japonica (F_ST=0.589). Structure analysis shows a clear separation of cultivated subpopulations at every K value, but genetic components were admixed within the wild illustrating the same genetic background with japonica and indica in some proportion.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.57 no.2
• /
• pp.129-136
• /
• 2024

Lactic acid bacteria (LAB) growth in processed meat products produces slime. In this study, 10 different biofilm-forming LAB, including Leuconostoc mesenteroides, Lacticaseibacillus paracasei, Levilactobacillus brevis, Lactiplantibacillus plantarum, Leuconostoc citreum, Weissella viridescens, and Latilactobacillus sakei, were isolated from various meat products and identified based on 16S rRNA gene analysis. To inhibit biofilm formation by LABs, Eisenia bicycles methanolic extract (EB) and ethyl acetate soluble fraction (EA) were used as antibacterial and antibiofilm agents, respectively. Furthermore, EA and EB were employed to synthesize gold nanoparticles (AuNPs) such as EB-AuNPs and EA-AuNPs, which could serve as antibiofilm agents against the isolated LAB. These findings demonstrate that EA, EB-AuNPs, and EA-AuNPs exhibit significant antibacterial activity against the isolated LAB. Furthermore, EB-AuNPs reduced L. citreum biofilm production, whereas EA-AuNPs inhibited L. mesenteroides and L. brevis biofilm formation. The current results suggest that EB-AuNPs and EA-AuNPs can be used as nanomaterials to inhibit LAB that form biofilms on meat products.

• The Korean Journal of Food And Nutrition
• /
• v.37 no.1
• /
• pp.9-16
• /
• 2024

To produce super sweet corn sikhye, substituted for sweetener, the ratio of rice and super sweet corn was adjusted and processed with complex enzymes during saccharification, and their physicochemical and sensory properties were analyzed. The soluble solid content of the control and Corn-5 showed significantly high content at 13.50 °Brix, and the reducing sugar content of Corn-5 showed the highest content at 9.45%. The control showed the lowest free sugar content among all the experimental groups, excluding maltose content. In the enzyme-treated corn sikhye group, as the amount of super sweet corn increased, the content of sucrose decreased and the contents of glucose and fructose increased. The content of ascorbic acid and polyphenol compounds increased as the amount of super sweet corn increased. DPPH and ABTS radical scavenging abilities increased with increasing ratio of super sweet corn and enzyme treatment compared to the control. In the case of sensory evaluation, Corn-3, which substituted 30% of super sweet corn for rice and treated with enzymes, showed higher evaluations in taste, sweetness, and overall preference than those of the control.

• Journal of Animal Science and Technology
• /
• v.66 no.2
• /
• pp.398-411
• /
• 2024

Upregulation of the nutritional value of feed is the major target of various studies in the livestock industry, and dietary enzyme supplementation could aid in digesting the nondegrading nutrients of grains in feed ingredients. Dried distillers' grains with solubles (DDGS) is a byproduct of the fermentation process in the beverage industry and can be used as a large supply source of fiber in feed. Therefore, we conducted an experiment with male broiler chickens to investigate the effect of various types of enzymes on DDGS and compare the efficacy of single enzyme and multienzyme complexes on growth performance and gut environments in broiler chickens. We used 420 1-day-old broiler chickens (Ross 308), and they were allotted into 4 dietary treatments with seven replications (CON, corn-soybean meal [SBM] diet; NC, DDGS supplemented diet; SE, 0.05 % of mannanase supplemented DDGS-based diet; MC, 0.10% of multienzyme complex (mannanase and xylanase, glucanase) supplemented DDGS-based diet. The dietary exogenous enzyme in the DDGS-supplemented diet could improve growth performance as much as the growth of the control group, and digestibility of dry matter, crude protein, and gross energy were significantly increased by enzyme addition in groups of chicks fed DDGS-supplementation diet. Moreover, the populations of pathogenic bacteria, coliforms, and Bacteroidetes were significantly decreased by enzyme supplementation, which might lead to improved gut mucus-secreting cells and inflammatory cytokines in the jejunum. Collectively, dietary single enzyme and multienzyme complexes could improve gut environments, including intestinal immune responses and gut microbial population, and lead to improvement of growth performance in broiler chickens.

• Journal of Animal Science and Technology
• /
• v.66 no.1
• /
• pp.178-203
• /
• 2024

Constipation, which refers to difficulties in defecation and infrequent bowel movement in emptying the gastrointestinal system that ultimately produces hardened fecal matters, is a health concern in livestock and aging animals. The present study aimed to evaluate the potential effects of dairy-isolated lactic acid bacteria (LAB) strains to alleviate constipation as an alternative therapeutic intervention for constipation treatment in the aging model. Rats were aged via daily subcutaneous injection of D-galactose (600 mg/body weight [kg]), prior to induction of constipation via oral administration of loperamide hydrochloride (5 mg/body weight [kg]). LAB strains (L. fermentum USM 4189 or L. plantarum USM 4187) were administered daily via oral gavage (1 × 10 Log CFU/day) while the control group received sterile saline. Aged rats as shown with shorter telomere lengths exhibited increased fecal bulk and soften fecal upon administration of LAB strains amid constipation as observed using the Bristol Stool Chart, accompanied by a higher fecal moisture content as compared to the control (p < 0.05). Fecal water-soluble metabolite profiles showed a reduced concentration of threonine upon administration of LAB strains compared to the control (p < 0.05). Histopathological analysis also showed that the administration of LAB strains contributed to a higher colonic goblet cell count as compared to the control (p < 0.05). The present study illustrates the potential of dairy-sourced LAB strains as probiotics to ameliorate the adverse effect of constipation amid aging, and as a potential dietary intervention strategy for dairy foods including yogurt and cheese.

• Food Science and Preservation
• /
• v.9 no.3
• /
• pp.321-326
• /
• 2002

Paeksulkis(Korean rice cake) containing 0-0.5% chitosan were prepared for test the quality of microbiological, mechanical and sensory characteristics. The pH of Paeksulkis was 5.65 without chitosan and that was about 7.0 with 0.05-0.5% level of chitosan. In Hunter's color values of Paeksulkis of control, the lightness(L) was 84.28, redness(a) was -1.56 and yellowness(b) was 7.68. The lightness(L), redness(a) and yellowness(b) were increased with increasing concentration of chitosan in Paeksulkis. In mechanical characteristics of Paeksulkis, cohesiveness and springiness were the highest in control group while strength, hardness, gumminess and brittlenes were higher in chitosan added group than control group. In sensory evaluation of Pasksulkis, control group obtained the highest score in color, texture, after swallowing and overall quality(p<0.05) but chitosan added group obtained higher scores in moisture than control(p<0.05). Total bacterial counts(TBC) of Paeksulgis immediately before storage were 4.2∼9.2$\times$10$^2$CFU/g and those of control increased for 2 weeks, reached at 7.4$\times$10$\^$5/ CFU/g and then decreased about 1 log cycle for 2 weeks during storage at 5$\^{C}$. TBC of Paeksulgis added 0.3∼0.5% of chitosan were 2 log cycles lower than that of control at the end of storage at 5$\^{C}$. TBC of Pasksulgis control increased to 10$\^$8/ CFU/g during storage at 20$\^{C}$ but that of 0.5% chitosan added group was 1 log cycle lower than control at the end of storage. Shelf-life extension of Paeksulkis by chitosan was more effective during storage at 5$\^{C}$ than at 20$\^{C}$.

• Korean journal of food and cookery science
• /
• v.26 no.1
• /
• pp.62-71
• /
• 2010

The followings describes the result of making doenjang with added licorice (Glycyrrhiza uralensis) powder. and investigating its sensory characteristics and physicochemical quality. General preference was high at 20% salinity and 2% licorice (LD204), and 16% salinity and 2% licorice (LD162). The moisture content was unchanged in the control group, while it was reduced in LD204 and LD162 in the first week of fermentation, but showed little change after then. pHs were all in the range 5.90~5.97 on day 0, but decreased from 5.90 to 5.72 in the control group in the fifth week. LD204 changed from 5.95 on day 0to 5.42 in the first week, and then it gradually increased again and became 5.93 in the fifth week, which was similar to that of day 0. LD162 was 5.97 on day 0 and showed cyclic slight increases and decreases in the first week. It increased to 6.32 in the fifth week, which was higher than that of day 0 that is, its pH was higher than that of LD204. The acidity showed a difference right after it was made. In the control group, lactic acid content gradually increased from 0.16% on day 0 to the highest, 0.59%, in the fourth week. It slightly decreased in the fifth week. LD204 slowly increased from 0.25% on day 0 to a maximum, 0.50%, in the fourth week. It also slightly decreased in the fifth week, quite similarly to that of the control group. LD162, gradually increased from 0.22% on day 0 to the highest, 0.49, in the third week, and decreased after the fourth week. Salinity was 29.5%, 22.0%, and 18% in each of the control group, LD204, and LD162 on day 0 but increased to 34.0%, 29.0%, and 26.0% in the fifth week. Soluble solid was $32^{\circ}Brix$, $28^{\circ}Brix$, and $26^{\circ}Brix$ in each of the control group, LD204, and LD162 on day 0, but slightly increased to $40^{\circ}Brix$, $32^{\circ}Brix$, and $30^{\circ}Brix$ on the fifth day. It is thought that because of the sweetness of licorice, the higher-salinity doenjang earned a higher sensory test score than that of traditional doenjang. If its salinity is lowered a little, it could be used as a sauce, even possibly having medical effects as well.