H. Kim

Although pork loins is not a tough meat, they need to develop for meat products with a soft texture for the elderly. This study focused on the physicochemical properties and tenderness characteristics of pork loin injected with green kiwifruit juice (GRJ) and gold kiwifruit juice (GOJ) during various incubation times. In addition, the antioxidant activities of hydrolysate derived from the hydrolysis of pork loin by kiwifruit juice protease were evaluated.The pork loin was injected with 10% and 20% GRJ and GOJ, under various incubation times (0, 4, 8, and 24 h). Then, the physicochemical properties and tenderness of pork loins. 2,2- diphenyl-1-picrylhydrazyl (DPPH) and reducing power were conducted to determine hydrolysate's antioxidant activities derived from pork loin's hydrolysis by kiwifruit juice protease.GRJ had greater tenderizing ability than GOJ, even at the 10% addition. When kiwifruit juice was injected into pork loin, the tenderness increased with increasing incubation time. This was confirmed by the decrease in intensity of the myosin heavy chain (MHC) band in SDS-PAGE. In particular, the MHC band decreased at 8 h for both 10% GRJ and 20% GOJ and at 4 h for 20% GRJ alone. The highest myofibril fragmentation index and peptide solubility were observed in pork loin treated with 20% GRJ compared to the other treatments during incubation. The 10% GRJ and 20% GOJ treatments showed similar levels of antioxidant activity of the protein hydrolysates in pork loin, and 20% GRJ showed the highest activity among the treatments.Kiwifruit juice had protease activity, and GRJ was more useful for the tenderness of meat products than GOJ. Thus, GRJ at 10% could be a potential agent to tenderize and enrich the natural antioxidant activity through the proteolysis of pork loin.

This study was performed to evaluate physico-chemical properties and antioxidant activity of pork patties with tomato powder as affected by water solubility.Fresh tomatoes were homogenized and dried in a 60°C oven.Dried tomato powder was added to double deionized-water and stirred.The soluble and insoluble portions were collected by freeze-drying.Thus, total dried powder (T1) and water soluble (T2) and insoluble powders (T3) were prepared for the experiment.Pork patties containing 0.5% water insoluble powder had the highest redness and yellowness values among the treatments (p<0.05).Thiobarbituric acid reactive substance values of pork patties containing 0.5% dried tomato powder were lower than those of the control (p < 0.05) and not different from those of the reference (0.01% BHT).Total bacteria and Enterobacteriaceae (VRB) tended to increase with increasing storage time from 0 to 14 d; however, these values were not statistically different among treatments.These results suggest that lipid oxidation may be suppressed by adding tomato powder to pork patties; thus, tomato powder could be used as a natural antioxidant in meat products as a partial replacement for synthetic antioxidants.

Fatty acid ω-3 desaturase (FAD) is the key enzyme catalyzing the formation of trienoic fatty acids.We utilized an Arabidopsis FAD7 gene and the seven independent transgenic rice plants harbouring 1 to 3 copies of this gene were generated.The expression of FAD7 mRNA was different among independent transgenic lines regardless of the copy number.The total linolenic acid (18:3) contents reduced by about 7 -32 % in transgenic rice plants but the linoleic acid (18:2) content increased accordingly.With or without wounding treatments, the jasmonate content was higher in transgenic lines than in wild-type rice plant.The transgenic lines overproducing jasmonate also showed increased expression of PR1b mRNA and allene oxide synthase in response to wounding.

Welsh onion (Allium fistulosum L.) is a very popular, medicinal and functional vegetable in East Asian countries. Welsh onion can be processed into different cuts and widely used as flavoring agent in food processing. In this study, the effects of wounding intensity (slices, pieces, and shreds) and storage temperature (4 and 20 °C) on postharvest quality and antioxidant activity of fresh-cut Welsh onions were studied. Our results showed that increased wounding intensity and higher storage temperature both led to the sharp rise of respiration rate, and the increasing loss of pungency, soluble solids content and ascorbic acid. On the other hand, the increase of phenylalanine ammonia lyase activity, the accumulation of phenolic compounds and the enhancement of antioxidant capacity were intensified with increased wounding intensity and higher storage temperature. The shelf life of 4 °C stored slices, pieces and shreds was determined to 5 d, while for 20 °C stored samples, this threshold was shortened to 1.5, 1.5 and 1 d, respectively. Thus, our results suggested that increased wounding intensity and higher storage temperature reduce postharvest quality and shorten shelf-life, but increase antioxidant activity of fresh-cut Welsh onions.