Enzymatic hydrolyzation of Cordyceps militaris mushroom extracts and its effect on spent hen chicken.

OBJECTIVE: This study was aimed to investigate the effect of fresh and dried hydrolyzed Cordyceps militaris (CM) mushroom with proteolytic enzymes; bromelain (CMB), flavorzyme (CMF), and mixture of bromelain: flavorzyme (CMBF) on quality properties of spent hen chicken. METHODS: Mushroom extract (CME) were combined with three proteolytic enzyme mixtures that had different peptidase activities; stem bromelain (CMB), flavorzyme (CMF), and mixture of stem bromelain:flavorzyme (CMBF) at (1:1). The effect of these hydrolysates was investigated on spent hen breast meat via dipping marination. RESULTS: Hydrolyzation positively alters functional properties of CM protease. in which bromelain hydrolyzed group (CMB) displayed the highest proteolytic activity at 4.57 unit/mL. The antioxidant activity had a significant increment from 5.32% in CME to 61.79% in CMB. A significantly higher emulsion stability index and emulsification activity index compared to CME were another result from hydrolyzation (p<0.05). Texture properties along with the shear force value and myofibrillar fragmentation index were notably improved under CMB and CMBF in fresh condition. Marination with CM mushroom protease that was previously hydrolyzed with enzymes was proven to also increase the nucleotide compounds, indicated by higher adenosine 5'-monophosphate (AMP) and inosine 5'-monophosphate (IMP) in hydrolysate groups (p<0.05). The concentration of both total and insoluble collagen remained unchanged, meaning less effect from CM protease. CONCLUSION: This study suggested the hydrolyzation of CM protease with bromelain or a mixture of bromelain:flavourzyme to significantly improve functional properties of protease and escalate the taste-related nucleotide compounds and texture profiles from spent hen breast meat.

Physicochemical Features and Volatile Organic Compounds of Horse Loin Subjected to Sous-Vide Cooking.

The purpose of this study was to evaluate the effect of temperature and time of sous-vide cooking method on the characteristics of Thoroughbred horse loin. Sliced portions (200 ± 50 g) were cooked by boiling (control) and sous-vide (65 and 70 °C for 12, 18, and 24 h). The samples were analyzed for proximate composition, pH, color, texture, microstructure, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), microbiology, volatile organic compounds (VOCs), nucleotide content, and fatty acids composition. The color analysis showed decreased redness at elevated temperatures. Improved tenderness, demonstrated by reduced shear force values (36.36 N at 65 °C for 24 h and 35.70 N at 70 °C for 24 h). The micrographs indicated dense fiber arrangements at 70 °C. The SDS-PAGE revealed muscle protein degradation with extended sous-vide cooking. The VOC analysis identified specific compounds, potentially distinctive markers for sous-vide cooking of horse meat including 1-octen-3-ol, decanal, n-caproic acid vinyl ester, cyclotetrasiloxane, octamethyl, and 3,3-dimethyl-1,2-epoxybutane. This study highlights the cooking time's primary role in sous vide-cooked horse meat tenderness and proposes specific VOCs as potential markers. Further research should explore the exclusivity of these VOCs to sous-vide cooking.

Effects of Dipping Chicken Breast Meat Inoculated with Listeria monocytogenes in Lyophilized Scallion, Garlic, and Kiwi Extracts on Its Physicochemical Quality.

This study was conducted to evaluate the antioxidant and antimicrobial activities of lyophilized extracts of scallions (Allium fistulosum L., SLE), garlic (Allium sativum, GLE), and gold kiwi (Actinidia chinensis, GKE) and their effects on the quality of chicken breast meat inoculated with L. monocytogenes during storage for 9 days at 4°C. The lowest minimum inhibitory concentration and minimum bactericidal concentration (25 and 100 mg/mL, respectively) against L. monocytogenes were observed for SLE and GLE, respectively. GKE had the lowest half-maximal inhibitory concentration (IC50) for 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (5.06 mg/mL). The pH values of meat inoculated with L. monocytogenes and dipped in 1% SLE (LSLE), 1% GLE (LGLE), or 1% GKE (LGKE) were lower than that of the control on day 3 of storage (p<0.05). The initial population of L. monocytogenes in meat was 4.95-5.01 Log CFU/g. However, the population in the LSLE (5.73 Log CFU/g) was lower than that in the control (6.23 Log CFU/g) on day 5 (p<0.05). The volatile basic nitrogen value of the LSLE (19.90 mg/100 g) was lower than that of the control (24.38 mg/100 g) on day 7 (p<0.05). Moreover, treatment with SLE resulted in the maintenance of meat quality and reduced the population of L. monocytogenes on the meat. Thus, SLE may be used as an alternative natural and environmentally friendly sanitizer for reducing L. monocytogenes contamination in the chicken meat industry.

Relationship between quality and freshness traits and torrymeter value of beef loin during cold storage.

In this study, we evaluated the relationship between quality and freshness traits and torrymeter value of beef loin during storage for 18 days at 4 °C to determine the torrymeter value that defines the maximum shelf life of the meat. The pH, total aerobic bacteria (TAB), and volatile basic nitrogen (VBN) value increased, while the torrymeter value decreased during the storage. The torrymeter value highly correlated with VBN (P < 0.0001), pH (P < 0.0001), TAB (P < 0.0001), instrumental colour a* value (P < 0.0001), and overall acceptability (P < 0.001). Two linear equations were established as the result of stepwise multiple linear regression analysis. According to the equations, the beef loin is completely spoilt if the torrymeter value is 11.82 or less and if the VBN value and a* value are 20 mg/100 g and 18, respectively.

Relation among quality traits of chicken breast meat during cold storage: correlations between freshness traits and torrymeter values.

The aim of this study was to evaluate the relation among the quality and freshness traits of chicken breast meat during storage for 12 d at 4°C. In addition, correlations between freshness traits and torrymeter values were examined. The L* and a* value of the color was constant; however, the b* value increased on day 5 of storage (P < 0.05). The shear force value significantly decreased, whereas the 2-thiobarbituric acid reactive substances value significantly increased during storage. Regarding the sensory properties, the off-odor and the drip loss increased along with the decrease in color and overall acceptability evaluated by the panelist. The pH, total microorganism counts, and volatile basic nitrogen (VBN) value of chicken breast significantly increased following storage, whereas the torrymeter value and overall acceptability of chicken breast meat significantly decreased from 12.80 to 4.53 and from 6.14 to 1.86, respectively. The VBN value was positively correlated with the pH and total microorganism counts, and the pH value was positively correlated with the total microorganism counts. The torrymeter value was associated with the VBN (-0.918, P < 0.01), pH (-0.973, P < 0.001), total microorganism counts (-0.975, P < 0.001), and overall acceptability (0.884, P < 0.01). These results suggest that the tested traits highly correlate with torrymeter value and it can be used as an indicator of freshness of chicken meat.

Physicochemical and Functional Characterization of Blue-Shelled Eggs in Korea.

The aim of this study was to compare the quality and physicochemical characteristics of blue-shelled eggs (BE) and conventional eggs (CE). Proximate composition, quality, pH value, shell color, collagen content, fatty acid composition, total cholesterol, α-glucosidase inhibition activity, and antioxidation activity were determined. The proximate composition, general qualities, and pH values of CE and BE showed no significant differences, except in moisture composition, weight, and shell thickness. Moisture content and weight of BE were significantly lower than those of CE. However, shell thickness and weight of BE were higher than those of CE (p<0.05). Lightness of BE was significantly higher than that of CE (85.20 vs. 58.80), while redness (a*) and yellowness (b*) of BE were lower than those of CE (a*: -4.75 vs. 14.20; b*: 10.45 vs. 30.63). The fatty acid [C18:1n7 (cis-vaccenic acid) and C18:3n6 (gamma-linolenic acid)] contents of BE were significantly higher than those of CE. The total cholesterol contents of BE and CE were similar. DPPH radical scavenging activity of BE was significantly higher than that of CE (40.78 vs. 35.35). Interestingly, α-glucosidase inhibition activity of whole egg and egg yolk in BE (19.27 and 36.06) was significantly higher than that of whole egg and egg yolk in CE (13.95 and 32.46). This result indicated that BE could potentially be used as a functional food material. Further studies are required to evaluate the specific compounds that affect functional activity.