Effects of an Extract from Olive Fruits on the Physicochemical Properties, Lipid Oxidation and Volatile Compounds of Beef Patties

Effect of cinnamon powder on quality attributes and off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken

The effect of cinnamon powder on the quality and mitigation of off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken (Woorimatdag No. 1, WRMD1) was investigated. The WRMD1 drumsticks were categorized into 5 groups: conventional thawing (16 h, CT), long-term thawing (48 h, LT), cinnamon powder added into 'LT' as marinade (0.03%, CM) or incorporated into the batter (1.35%, CB), and long-term thawing with cinnamon powder incorporated both in the marinade and batter (0.03% + 1.35%, CMB). The crude fat content was significantly higher in the CT and CMB than that of the CB. The CM, CB, and CMB showed significantly lower levels of 2-thiobarbituric acid reactive substance compared with the CT and LT. The predominant fatty acids in all treatments were C18:1n9, C18:2n6, and C16:0. The LT displayed lower total unsaturated fatty acid content than the CT (P < 0.05). The CM effectively decreased lipid oxidative volatiles, such as 1-octanol, 1-octen-3-ol, and 2-octen-1-ol, (E), in the LT (P < 0.05). Both the CM and CB showed an inclination to increase specific pyrazines associated with pleasant notes compared with the LT, and showed higher levels of pyrazines, such as pyrazine, 2-ethyl-6-methyl-, and pyrazine, 3-ethyl-2,5-dimethyl-, than those of the CMB (P < 0.05). The CM contained higher levels of 2,3-butanedione when compared with the other groups (P < 0.05). Multivariate analysis demonstrated that cinnamon had an effect in discriminating the treatment groups with cinnamon addition from both the CT and LT, whereas the CM, CB, and CMB formed distinct clusters. The CM and CMB received significantly higher aroma scores from panelists in comparison to the other groups. These findings suggest that the CM (0.03% cinnamon powder) can be used to enhance the aroma in fried WRMD1 drumsticks by reducing or masking the off-flavor volatiles associated with long-term thawing.

Potential inhibitory effect of carbon dioxide on the spoilage behaviors of Pseudomonas fragi in high-oxygen packaged beef during refrigerated storage

Pseudomonas fragi is a dominant meat spoilage organism under high-oxygen modified atmosphere packaging (HiOx-MAP). This work investigated the effects of CO₂ on P. fragi growth and the related spoilage phenomena of HiOx-MAP beef. Minced beef incubated with P. fragi T1, a strain owning the strongest spoilage potential among isolates, was stored under CO₂-enriched HiOx-MAP (TMAP; 50% O₂/40% CO₂/10% N₂) or non-CO₂ HiOx-MAP (CMAP; 50% O₂/50% N₂) at 4 °C for 14 days. Compared to CMAP, TMAP maintained sufficient O₂ levels to endow beef with higher a* values and meat color stability due to lower P. fragi counts from day 1 (P < 0.05). TMAP samples also showed lower (P < 0.05) lipase activity and protease activity within 14-days and 6-days than CMAP samples respectively. TMAP delayed the significantly increased pH and total volatile basic nitrogen contents occurred in CMAP beef during storage. Despite TMAP markedly promoted the lipid oxidation associated with higher concentrations of hexanal and 2,3-octanedione than CMAP (P < 0.05), TMAP beef retained an acceptable organoleptic odor due to a CO₂-inhibition on the microbial-induced 2,3-butanedione and ethyl 2-butenoate formation. This study provided a comprehensive insight into the antibacterial mechanism of CO₂ on P. fragi in HiOx-MAP beef.

Effects of Process Parameters on the Quality of Suantang Beef

Suantang beef is a traditional delicious Chinese food cooked in Suantang (ST, a sour soup fermented by microorganisms). However, the impact of ST on beef quality is unclear, and the process of ST beef lacks unified technical standards. In the presented study, we found that the additional amount of salt, cooking time, meat thickness, and beef-ST ratio significantly affect the quality of ST beef. After optimization, it was found that when salt addition was 1%, cooking time was 3 min, meat thickness was 2 cm, and beef-ST ratio was 40%, the color determined by colorimeter, texture determined by texture analyzer, and sensory scores of beef cooked by ST were improved compared with boiled beef. ST decreased the pH value and cathepsin L activity of beef, increased the content of organic acid, and changed the protein composition of beef. ST made the beef have higher hardness, and have better chewiness and cohesion. At the same time, ST reduced the disagreeable odors of beef and improved beef flavor. In addition, 88 volatile compounds were detected in ST beef by HS-SPME/GC-MS. According to odor, threshold, and odor activity value (OAV), 24 critical aroma-active compounds were confirmed in ST beef. This study provides a basis for the potential industrialized production of ST beef.

Spoilage of tilapia by Pseudomonas putida with different adhesion abilities

Four Pseudomonas putida strains isolated from spoiled tilapia were divided into three adhesion abilities—high, medium, and low—by an in vitro mucus model. Four strains had no significant difference in spoilage ability to the inoculated fish fillets. However, according to the in vivo experiment, the spoilage caused by the four P.putida was positively correlated with their adhesion abilities. High adhesion strains not only caused more TVB-N in chilled fish, but also activated the spoilage activity of intestinal flora. The diversity of intestinal flora and the changes in volatile components in fish were detected by high-throughput sequencing and SPME-GC/MS. The strains with high adhesion abilities significantly changed the intestinal flora, which led to a significant increase in low-grade aldehydes, indole, and esters in flesh of fish, as well as the production of a fishy and pungent odor. The intestinal adhesion ability of spoilage bacteria was considered the key factor in spoilage of chilled fish.

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A positive correlation between the intestinal adhesion ability of P.putida and the spoilage ability in vivo.

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P.putida affected the intestinal microflora and led to increase in fishy and pungent odor.

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The intestinal adhesion ability of P.putida was considered as a key factor in spoilage.

Preparation and Characterization of Bio-Nanocomposites Film of Chitosan and Montmorillonite Incorporated with Ginger Essential Oil and Its Application in Chilled Beef Preservation

In this study, bio-nanocomposite films containing different proportions of ginger essential oil (GEO), chitosan (Ch), and montmorillonite (MMT) were prepared and characterized, and the antibacterial effect of bio-nanocomposite films on chilled beef was evaluated. Fourier transform infrared analysis showed a series of intense interactions among the components of the bio-nanocomposite films. The infiltration of GEO increased the thickness of the film, reduced the tensile strength of the film, and increased the percentage of breaking elongation and the water vapor permeability. The migration of phenols in the films began to increase exponentially and reached equilibrium at about 48 h. The bio-nanocomposite films (Ch +0.5% GEO group, and Ch + MMT + 0.5% GEO group) effectively delayed the rise of pH, hue angle, and moisture values of chilled beef with time and slowed down the lipid oxidation and the growth of surface microorganisms on chilled beef. Altogether, the prepared biological nanocomposites can be used as promising materials to replace commercial and non-degradable plastic films.