Effect of Different Storage-Temperature Combinations on Longissimus dorsi Quality upon Sous-vide Processing of Frozen/Thawed Pork.

This study investigated the effect of storage state (chilled state on sous-vide, CS; frozen state without thawing on sous-vide, FS; and frozen/thawed states on sous-vide, TS) and sous-vide cooking temperature (65°C and 72°C) on the longissimus dorsi muscle quality of pork. FS showed a higher moisture content than that of CS and TS (p<0.001), whereas both FS and CS showed higher expressible moisture loss than that of TS (p<0.001). FS showed a lower cooking loss (p<0.001) than that of CS and TS. FS and TS exhibited significantly higher lipid oxidation than that of CS. Carbonyl and sulfhydryl content were not significantly affected by the storage treatment. FS and TS exhibited lower shear force than that of CS (p<0.001). FS and TS showed higher springiness than that of CS (p<0.001), FS exhibited lower gumminess than that of CS and TS (p<0.01). Sous-vide treatment at 65°C exhibited significantly higher moisture content and lower expressible moisture loss, cooking loss, and total and sarcoplasmic protein than those at 72°C. Shear force and springiness of 65°C-treated groups were lower than those of 72°C-treated groups (p<0.01). Cooking temperature significantly influenced overall acceptability, whereas the storage state did not affect the overall acceptability. These results indicated that meat quality might be improved upon cooking from the frozen or frozen/thawed state using sous-vide when compared with traditional processing.

Effects of Heating Time and Temperature on Functional Properties of Proteins of Yellow Mealworm Larvae (Tenebrio molitor L.).

Although the yellow mealworm (Tenebrio molitor L.) is a promising alternative protein source, the effects of processing conditions on functional properties are unclear. In this study, a protein extract of yellow mealworm larvae (PEYM) was subjected to different heat temperature (55°C, 75°C, and 95°C) with different time (20, 40, and 60 min) to evaluate the functional properties and protein oxidation. Different heat temperature treatment significantly affected the exposure of surface hydrophobicity of the proteins and protein molecule aggregation, which reached maximum levels at 95°C for 60 min. Protein oxidation was inversely proportional to the temperature. Both the highest carbonyl value (1.49 nmol/mg protein) and lowest thiol value (22.94 nmol/mg protein) were observed at 95°C for 60 min. The heating time-temperature interaction affected several functional properties, including solubility, emulsifying potential, and gel strength (GS). Solubility decreased near the isoelectric point (pH 5 to 6). As the temperature and heating time increased, emulsifying properties decreased and GS increased. The oil absorption capacity and foaming properties decreased and the water absorption capacity increased. These results confirmed that PEYM is a suitable source of proteins for processing and applications in the food industry.

A comparison of dry and wet aging on physicochemical and sensory characteristics of pork loin with two aging times.

This study investigated the effects of aging methods (wet aging and dry aging) and aging times (7 and 14 days) on the physicochemical and sensory characteristics of meat quality using pork loin. Dry-aged loin (DA) had significantly lower moisture content and higher crude fat protein content than wet-aged loin (WA). The pH of DA was significantly higher than that of WA and it increased with the aging time. DA showed lower cooking loss and higher aging loss than WA (p < 0.001). Lipid oxidation and metmyoglobin content of DA were higher than those of WA (p < 0.001). Shear force in DA was lower than that in WA (p < 0.001) and myofibril protein index (MFI) increased in DA. In addition, DA recorded higher scores of roast color, flavor and overall acceptability compared to WA. These results suggested that the application of dry-aging on pork improved physicochemical, textural and sensory characteristics.

Antioxidant and antimicrobial activities of fresh garlic and aged garlic by-products extracted with different solvents.

This study aims to investigate antioxidative and antibacterial properties of fresh garlic (non-aged, NG) and aged garlic (AG) by-products extracted with distilled water, ethanol, or chloroform. To determine their antioxidative and antibacterial capacities, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assay, and H2O2 radical scavenging activity, Fe2+ chelating activity, total ferric reducing antioxidant power (FRAP), and disc diffusion tests were performed. Total phenol and flavonoid contents from distilled water extract of AG were significantly higher than those of NG. DPPH, ABTS, FRAP, and H2O2 scavenging activities of distilled water extract of AG were higher than those of NG. However, Fe2+ chelating activities of ethanol and chloroform extracts were higher than those of distilled water extracts for both NG and AG. Antibacterial effects of AG were higher than those of NG. In conclusion, aged garlic showed more potent antioxidant and antibacterial effects than fresh garlic.

Erratum to: Effect of Aging Process and Time on Physicochemical and Sensory Evaluation of Raw Beef Top Round and Shank Muscles Using an Electronic Tongue.

[This corrects the article DOI: 10.5851/kosfa.2017.37.6.823.].

Effect of Allium hookeri Root on Physicochemical, Lipid, and Protein Oxidation of Longissimus Dorsi Muscle Meatball.

The antioxidant effects of Allium hookeri root (AHR) were investigated by evaluating lipid and protein oxidation in meatballs during refrigerated storage at 4±1℃. AHR was mixed at concentrations of 0.5% (w/w, T2) and 1% (w/w, T3) with minced longissimus dorsi muscle. Meatballs containing AHR (T2 and T3) were compared to those containing 0.05% (w/w) ascorbic acid (T1) as a reference and without antioxidant as a control. The 2-thiobarbituric acid reactive substances (TBARS) value, disulfide bond formation, carbonyl contents, and volatile basic nitrogen (VBN) value of T2 were lower than those of the control during storage (p<0.05). The pH values of T2 and T3 were higher than that of the control (p<0.05). Texture profile analysis of T2 revealed a lower value compared to the control (p<0.05). Therefore, the VBN value, TBARS value, disulfide bond formation, and carbonyl content in meatball containing AHR were lower than those of the control meatball. These results indicate that AHR improves the quality of meat products and functions as an antioxidant.

Effect of Aging Process and Time on Physicochemical and Sensory Evaluation of Raw Beef Top Round and Shank Muscles Using an Electronic Tongue.

The objective of this study was to determine the effect of aging method (dry or wet) and time (20 d or 40 d) on physical, chemical, and sensory properties of two different muscles (top round and shank) from steers (n=12) using an electronic tongue (ET). Moisture content was not affected by muscle types and aging method (p>0.05). Shear force of dry aged beef was significantly decreased compared to that of wet aged beef. Most fatty acids of dry aged beef were significantly lower than those of wet aged beef. Dry aged shank muscles had more abundant free amino acids than top round muscles. Dry-aging process enhanced tastes such as umami and saltiness compared to wet-aging process according to ET results. Dry-aging process could enhance the instrumental tenderness and umami taste of beef. In addition, the taste of shank muscle was more affected by dry-aging process than that of round muscle.