The objective of this study was to develop a palatability index for evaluating taste quality of pork through correlation and causality between fatty acids and taste related factors. Results of analysis of the components and taste evaluation among varieties showed that the taste quality of Duroc pork was the best. A correlation was found between fatty acids and taste evaluation factors. Saturated fatty acids (SFAs) and oleic acid increased the sweetness and savory taste, the preferred flavors, while sourness and bitterness, the non-preferred flavors, decreased, and thus positively affecting the taste. Polyunsaturated fatty acids (PUFAs) have been shown to have a negative effect on taste by decreasing their preferred taste while increasing their non-preferred taste. In addition, multiple regression between fatty acid and five taste factors showed that stearic acid and oleic acid increased the sweetness and savory taste, while myristic acid decreased the bitterness. Linolenic acid was found to be negatively affecting the taste by increasing non-preferred flavors. In conclusion, SFAs, oleic acid and linolenic acid were found to be the major factors affecting the taste of pork. Therefore, the results of this study can be used as an index to produce delicious pork for pig producers as well as help consumers to trust and purchase high quality domestic pork.
Low molecular weight hydrolysates from donkey bone extracts (LHDB) was prepared with different food enzymes, and its antioxidative, elastase and collagenase inhibitory, and fibroblast cell protection effects against photoaging were evaluated. Gelatin from donkey bone was extracted three times at 121℃ for 1 h and was lyophilized. The lyophilized powder (5 g) was dissolved in 95 mL distilled water with 1% FoodPro alkaline protease (A), 1% Protease P (P), 1% Protease M (M) and a 0.3% A + 0.3% P + 0.3% M (APM) mixture and was hydrolyzed for 3 h at 45℃. After enzyme inactivation at 90℃ for 10 min, the LHDBs hydrolyzed by A, P, M, and APM were separated by centrifugal filtration and were lyophilized and marked as LHDB-A, LHDB-P, LHDB-M, LHDB-APM. The LHDB-M showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline–6- sulphonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) than the other treatments (p<0.05). The elastase inhibition effect (37.49%) of LHDB-M were significantly higher than those of the other treatments (9.97-34.18%). The viability of human fibroblast cells (Hs68) after UVB irradiation was significantly increased by LHDB-M, indicating that it can be used as an antioxidant or as a UVB stress protector. However, further in vivo studies should precede its usage in the bioactive compound industry.
The objective of this study was to investigate the quality properties of sausages added with the atmospheric pressure plasma treated extract of Perilla frutescens Britton var. acuta Kudo (red perilla). The lyophilized powder of red perilla extract treated by atmospheric-pressure plasma contained 7.5 g kg-1 nitrite. Sausage samples were manufactured with the addition of sodium nitrite (Control), celery powder (Celery), or plasma-treated extract of red perilla (PTP) to obtain nitrite concentration of 70 mg kg-1. The residual nitrite content was the lowest in PTP during storage for 21 days at 4℃ (p<0.05). The total aerobic bacteria counts were higher in PTP than in Control and Celery during storage at 4℃ (p<0.05). Malondialdehyde content of sausages was significantly lower in PTP than in Control and Celery during storage (p<0.05). PTP showed the lowest L* value and the highest b* value among the tested sausage samples during storage (p<0.05). PTP received the low scores in all the sensory properties of sausages because of its inherent color and flavor. The results suggested that the plasma-treated extract of red perilla was an unsuitable natural nitrite source for cured meat products because of its adverse effect on sensory quality. However, natural nitrite source with increased nitrite content can be produced by the treatment of the natural plant extract with atmosphericpressure plasma.
In this study, effects of gelatin extracted from chicken feet powder and wheat fiber on physicochemical properties of gel were determined. Gel samples were prepared with different concentrations of chicken feet gelatin powder (2, 3, and 4%) and wheat fiber (0, 1, and 2%). Gel strength increased (p<0.05) with increasing concentrations of both chicken feet gelatin powder and wheat fiber. In each gel sample, melting point and apparent viscosity of the gel was affected by different chicken feet gelatin powder concentrations irrespective of the wheat fiber concentrations (0, 1, or 2%). The 4% chicken feet gelatin powder induced the highest melting point among all gel samples regardless of the wheat fiber concentration. The gel sample with 4% chicken feet gelatin powder and 2% wheat fiber showed the highest values (p<0.05). With the increasing concentrations of wheat fiber, CIE L* increased in gel samples with chicken feet gelatin powder at 3 and 4% (p<0.05). Lower CIE a* was observed in gel samples with wheat fiber at 1 and 2% compared to gel samples without wheat fiber (p<0.05). CIE b* of gel samples with 2% chicken feet gelatin powder was decreased as increasing the addition level of wheat fiber (p<0.05). Consequently, our studies show that chicken feet gelatin powder and wheat fiber mixture could be used as a food ingredient since they have various effects on physicochemical properties of gel such as an effect on gel strength, melting point, viscosity, and color.
In the case of foot-and-mouth disease (FMD), there is a great deal of impact on the national economy due to the disposal of diseases, the cost of disease control such as vaccination, reduction of productivity, and restriction of international trade of livestock products. Therefore, appropriate diagnostic methods for sensitive, accurate and rapid identification of virus serotypes are continuously required in terms of early prevention of FMD. This study was conducted to confirm the feasibility of immuno-PCR diagnostic method for the more sensitive detection of Korean FMD virus (FMDV). We synthesized a partial FMD type A viral gene. Protein antigen, monoclonal and polyclonal antibodies of FMDV were cloned, expressed and purified and then magnetic particles were attached to polyclonal antibodies and and oligomers to monoclonal antibodies for the immnuno-PCR. We confirmed the antigen-antibody and oligomer reaction using ELISA, Western blot, and real-time PCR. These results show that Korean FMDV can be detected by using difference of Ct values between positive group and negative group using immuno-PCR.. The results of this study also suggest that this technique will be the basis of the diagnosis method to detect Korean FMDV more sensitively in the future.