Application of concave induction cooking to improve the texture and flavor of braised pork

Long-term cooking may reduce the eating and nutritional quality attributes of meat products due to excessive oxidation. This study aimed to investigate the feasibility of concave induction to improve the quality of braised pork belly. Pork belly cubes were subjected to concave induction cooking (2000 W) or plane induction cooking (2000 W, traditional) for 60 min, 90 min, 120 min or 150 min. Then texture, fatty acid profile, lipid and protein oxidation, volatile flavor and sensory test in braised meat were evaluated. Compared with traditional method, concave induction cooking showed higher heating performance with shorter time to achieve a setting temperature. Compared with traditional cooking for 150 min, concave induction cooking for 60 min did not only produce a comparable volatile flavor and sensory scores, but also give better quality attributes, including lower hardness, chewiness, thrombogenicity values, PUFA/SFA value, lipid and protein oxidation. E‑nose results showed that samples cooked by concave induction for 60 min and 90 min showed a great similarity to those cooked by plane induction for 150 min. Concave induction cooking for 60 min also showed advantages to retain higher abundances of other volatile compounds including 2-pentylfuran, (E, E)-3,5-octadien‑2- one, 2, 3-octanedione, 2-decahydro‑1,6- dimethylnaphthalene when compared with plane induction cooking for 150 min.

Effect of Dietary Curcumin Supplementation on Duck Growth Performance, Antioxidant Capacity and Breast Meat Quality

This study aimed at examining the effects of curcumin supplementation on growth performance, antioxidant capacity, and meat quality of ducks. To investigate these effects, 600 healthy ducks were randomly assigned to four treatment groups with 10 replicates pens, and each pen contained 15 ducks. Ducks were fed a diet containing curcumin at levels of 0, 300, 400, and 500 mg kg−1 in different groups. The results demonstrated that curcumin supplementation is beneficial to the growth performance (p < 0.05) of ducks and antioxidant capacity (p < 0.05) of duck meat. In addition, dietary curcumin raised the meat quality of ducks, improving the meat color, increasing water-holding capacity, and inhibiting lipid and protein oxidation. In conclusion, the present study provides important insights into both the nutrient and qualities of ducks, finding that a dietary inclusion of 400–500 mg/kg of curcumin (kg−1) has the greatest effect.

The Influence of Butter and Oils on Oxidative Reactions during In Vitro Gastrointestinal Digestion of Meat and Fish

Oxidative reactions during cooking and gastrointestinal digestion of meat and fish lead to the formation of various lipid- and protein oxidation products, some of which are toxic. In the present study, it was investigated how the addition of 3% butter or oils affect lipid- and protein oxidation during cooking and in vitro digestion of meat (chicken thigh, chicken breast, beef) and fish (mackerel, cod). These muscle foods were selected based on their differences in heme-Fe and PUFA contents, and n-6/n-3 PUFA ratio, and therefore varying potential to form oxidation products during digestion. Without additional fat, mackerel digests displayed the highest n-3 PUFA oxidation (4-hydroxy-2-hexenal, propanal, thiobarbituric reactive acid substances), and chicken digests the highest n-6 PUFA oxidation (4-hydroxy-2-nonenal, hexanal), whereas both lipid- and protein oxidation (protein carbonyl compounds) were low in cod and beef digests. Lipid oxidative reactions were generally not altered by the addition of butter to any muscle matrix, whereas the addition of fish oil and safflower oil in different ratios (3:0, 2:1, 1:2, 0:3) as n-3 PUFA and n-6 PUFA source respectively, stimulated oxidative reactions, especially during digestion of beef. Since beef was considered the muscle matrix with the highest potential to stimulate oxidation in the added fat substrate, in a second experiment, beef was cooked and digested with 3% butter or seven commercial vegetable oils (sunflower-, maize-, peanut-, rapeseed-, olive-, rice bran- or coconut oil), all labeled ‘suitable for heating’. No relevant oxidative reactions were however observed during digestion of beef with any of these commercial vegetable oils.

Effect of α-tocopherol, rosemary extract and their combination on lipid and protein oxidation in beef sausages

This study focuses on the oxidative changes in lipids and proteins of beef sausages with incorporated a-tocopherol, rosemary extract or their combination during 3 months’ storage at 4°C. For this purpose, sausages were formulated with no antioxidant (Control, C), 200 ppm a-tocopherol (T), 200 ppm rosemary extract (R), and 100 ppm a-tocopherol + 100 ppm rosemary extract (TR). To observe oxidative changes in lipids; peroxide value, thiobarbituric acid reactive substances (TBARS), and total oxidation value (TOTOX), in proteins; sulfhydryl and carbonyl contents were measured. Use of antioxidants and storage time significantly affected oxidative stability of sausages (P<0.05). Antioxidants, individually or in combination, retarded lipid peroxidation and improve the oxidative stability of sausage during storage. The antioxidant combination showed synergistic effect on protein oxidation, as the lowest carbonyl contents were found in TR samples. As a result, a combination of antioxidants with different effect mechanisms could be the better option to prevent oxidative changes in meat products.

Impact of Various Dry-Aging Methods on Meat Quality and Palatability Attributes of Beef Loins from Cull Cow

The objective of this study was to determine the effect of various dry-aging methods on meat quality and palatability attributes of cull cow beef loins. Paired bone-in loins (M. longissimus lumborum) from 13 cull cow carcasses (Holstein, 42+ mo) were obtained at 5d postmortem, divided into four equal sections and randomly assigned into 4 aging methods (wet-aging [WA], conventional dry-aging [DA], dry-aging in water permeable bag [DWA], and UV-light dry-aging [UDA]). The beef sections were aged for 28d at 2°C, 65% relative humidity and 0.8 m/s airflow. Following aging, surface crusts and bones were removed and loin samples were collected for the meat quality, microbiological and sensory analyses.Results indicated that all dry-aged loins had greater moistureand trimming loss compared to WA (P&lt;0.05), while DWA had lower loss than DA and UDA (P&lt;0.05). No differences in shear force, cook loss and both lipid and protein oxidation across all treatments were observed (P&gt;0.05). Among all treatments, DWA exhibited the least color stability indicated by rapid discoloration observed in the sample, while UDA had color attributes comparable to WA throughout the whole display. Microbial analysis indicated that UDA had lower microbial concentration on the surface than the other samples (P&lt;0.05). The consumer panel analysis found that all loins were acceptable and the trained panel analysis indicated that DA loins had lower sour and fatty flavor attributes compared to WA (P&lt;0.05). The results indicate that dry-aging can potentially be utilized as the effective natural process to improve cull cow beef palatability without compromising other meat quality attributes or microbiological shelf-life.

Formation of Lipid and Protein Oxidation Products during In Vitro Gastrointestinal Digestion of Dry-Cured Loins with Different Contents of Nitrate/Nitrite Added

The effect of nitrate/nitrite (0, 37.5, 75, and 150 mg/kg) in the dry-cured loin formulation on the formation of lipid and protein oxidation products during in vitro digestion was evaluated. Dry-cured loins formulated with nitrate/nitrite resulted in significantly less lipid and protein oxidation than uncured loins before and after simulated digestion. Compared to loins added with 0 mg/kg nitrate/nitrite, dry-cured loins with 37.5, 75, and 150 mg/kg contained a significantly lower content of conjugated dienes, malondialdehyde, carbonyls, and non-heme iron, and higher amounts of nitrosylmioglobin and thiols. During in vitro digestion, the content of conjugated dienes, malondialdehyde, and carbonyls increased, while thiol content decreased, indicating the development of lipid and protein oxidative processes. At the end of the intestinal phase, the 75 mg/kg digests had a significantly higher content of conjugated dienes, while no differences were found among the other digests. During the in vitro intestinal phase (180 and 240 min), nitrate/nitrite curing resulted in significantly lower malondialdehyde concentrations in the 37.5, 75, and 150 mg/kg loin digests than in the uncured loin digests. No significant differences were observed at the end of the intestinal digestion phase between the cured loin digests. Digests of dried loins without nitrate/nitrite addition showed higher carbonyl contents than the nitrate/nitrite cured counterparts. The loss of thiols was significantly higher in loin digests without added nitrate/nitrite than in loin digests with different amounts of curing salts. The addition of 37.5 mg/kg nitrate/nitrite in the cured loin formulation prevents the formation of lipid peroxidation products and carbonyls from protein oxidation and thiol loss during digestion