Effects of the type of frying with culinary fat and refrigerated storage on lipid oxidation and colour of fried pork loin chops

Effect of heat treatments on the physicochemical and sensory properties of the longissimus thoracis muscle in unweaned Limousin calves

The aim of the study was to assess the effect of methods of heat treatment on selected quality parameters of longissimus thoracis muscle of Limousin calves, subjected to grilling, steaming, and sous vide cooking. The type of heat treatment did not significantly affect shear force or water activity. Cooking loss in the grilled and steamed meat was significantly higher than in the sous vide. While the content of vitamin E was significantly lower in the cooked meat, it was retained to the greatest degree in the grilled meat and least in the steamed meat. The TBARS index significantly increased during all cooking methods with the highest level in steamed meat. The sensory analysis revealed a preference for the sous vide and grilled meat, while the steamed meat received the lowest scores. Although veal is commonly assumed to be highly nutritious and palatable, its quality can be significantly influenced by the type of heat treatment.

Determinants of broiler chicken meat quality and factors affecting them: a review

Broiler production at mass level has already been achieved and now emphasis is being laid on increasing meat quality by altering various characteristics of broiler meat. Appearance, texture, juiciness, wateriness, firmness, tenderness, odor and flavor are the most important and perceptible meat features that influence the initial and final quality judgment by consumers before and after purchasing a meat product. The quantifiable properties of meat such as water holding capacity, shear force, drip loss, cook loss, pH, shelf life, collagen content, protein solubility, cohesiveness, and fat binding capacity are indispensable for processors involved in the manufacture of value added meat products. Nutrition of birds has a significant impact on poultry meat quality and safety. It is well known that dietary fatty acid profiles are reflected in tissue fatty acid. Management of poultry meat production is reflected mostly on consumption features (juiciness, tenderness, flavour) of meat. After slaughter, biochemical changes, causing the conversion of muscle to meat, determine final meat quality. Postmortem carcass temperature has profound effect on rigor mortis and the physicochemical changes observed in PSE muscles are attributed to postmortem glycolysis, temperature, and pH. Primary processing and further processing have become a matter of concern with respect to nutritional quality of broiler meat. Genetic variation among birds could contribute to large differences in the rate of rigor mortis completion and meat quality. Heritability estimates for meat quality traits in broilers are amazingly high (0.35-0.81), making genetic selection a best tool for improvement of broiler meat quality.

Effect of Cooking Conditions on Quality Characteristics of Confit Cod: Prediction by MRI

This study evaluates the effect of low temperature (60, 64 and 68 °C) and different times (15 and 20 min) of cooking on physicochemical and sensory characteristics of confit cod and analyzes confit cod in a non-destructive way by means of magnetic resonance imaging (MRI) and computer vision techniques. Higher scores for acceptability and flavor in 60 °C–20 min and 64 °C–20 min samples and some physicochemical differences were found. These results allow distinguishing four groups of confit cods as a function of cooking conditions – 60 °C–15 min/68 °C–15 min/68 °C–20 min/60 °C–20 min, 64 °C–15 min, 64 °C–20 min – and proposing to cook confit cod at 60–64 °C during 20 min. Prediction by means of computational texture features from MRI gave moderate-to-good correlation (0.6–0.75) for six quality attributes and very good-to-excellent relationship (0.75–1) for other six. Thus, computational texture features seem to be appropriate to determine the quality attributes of confit cod in a non-destructive way.

Quality changes of chicken meat jerky with different sweeteners during storage

Chicken meat jerky with high sugar content is popular intermediate-moisture meat product in Asia. Different types of sugar, sucrose and mixed sugar (sucrose: fructose: sorbitol 70: 15: 15), were evaluated to improve the quality of product. Quality changes of chicken meat jerky stored in vacuum and aerobic (33 and 75 %relative humidity, %RH) conditions were studied for suitable condition to extend shelf-life of product. The samples were determined the physical and chemical characteristics, as well as sensory evaluation during storage at room temperature. The moisture content and water activity (aw) of samples stored in 33 %RH conditions was continuously diminished during storage that related to harder texture and unacceptable quality in sensory evaluation. All samples stored in vacuum and 75 %RH condition demonstrated the lower shear force value than that stored in 33%RH condition (p < 0.05). Samples stored in vacuum condition had the lowest lipid oxidation (p < 0.05.) which corresponding to the highest scores in less rancidity and overall acceptance attributes. All samples stored in vacuum condition also had the highest acceptability in all sensory attributes (taste, rancidity, color and overall acceptance) followed by 75 %RH storage condition (p < 0.05). Samples prepared with mixed sugar could improve color and retard rancidity in chicken jerky meat product. Sample prepared with mixed sugar kept in vacuum condition had the lowest lipid oxidation and highest sensory score in overall acceptance attributes along the extended storage.

Oxidation of olive oil fortified with quercetin, caffeic acid, tyrosol and hydroxytyrosol

Purpose

– This paper aims to evaluate effects of the fortification of polyphenolic compound mixtures of quercetin, caffeic acid, tryrosol and hydroxytyrosol in olive oil oxidation.

Design/methodology/approach

– The authors measured olive oxidation initiated by copper using thiobarbituric acid reactive substance, as an indicator of lipid peroxidation.

Findings

– Overall, most mixture combinations exhibited oxidation similar to olive oil alone. Some mixture combinations of polyphenolic compounds acted as antioxidants; however, as the concentrations were changed, they became prooxidant in nature.

Research limitations/implications

– In vitro studies have limitations for extrapolation to in vivo and clinical studies.

Practical implications

– Such information will be useful in determining optimal concentrations and combinations of antioxidants for reducing rancidity and perhaps as models that could be used to modulate various chronic diseases that are associated with oxidative stress.

Originality/value

– Olive oil, along with fruits, vegetables and fish, are important constituents of health promoting diets, such as the Mediterranean diet. Active ingredients include monounsaturated fatty acids, oleic acid and a variety of antioxidants including various polyphenolic compounds.

Quality Evaluation of Chicken Nugget Formulated with Various Contents of Chicken Skin and Wheat Fiber Mixture

This study aimed to investigate the effects of various mixtures of the chicken skin and wheat fiber on the properties of chicken nuggets. Two skin and fiber mixtures (SFM) were prepared using the following formulations; SFM-1: chicken skin (50%), wheat fiber (20%), and ice (30%); and SFM-2: chicken skin (30%), wheat fiber (20%), and ice (50%). Chicken nugget samples were prepared by adding the following amounts of either SFM-1 or SFM-2: 0%, 2.5%, 5%, 7.5%, and 10%. The water content for samples formulated with SFM-1 or SFM-2 was higher than in the control (p<0.05), and increased with increasing the concentrations of SFM-1 and SFM-2. The addition of SFM-1 and SFM-2 had no significant effect on the pH of the samples. The lightness value of uncooked chicken nuggets was higher than that of cooked chicken nuggets for all the samples tested. Chicken nuggets formulated with SFM-1 and SFM-2 displayed higher cooking yields than the control sample. The hardness of the control sample was also lower than the samples containing SFM-1 and SFM-2. The sensory evaluation showed no significant differences between the control and the samples containing SFM. Therefore, the incorporation of a chicken skin and wheat fiber mixture improved the quality of chicken nuggets.

Quality characteristics of fried lamb nuggets from low-value meat cuts: Effect of formulation and freezing storage

This study revealed the possibility of manufacturing prefried lamb nuggets from low-value cuts (flank) and evaluated the effect of formulation (50:50 vs. 20:80 of leg/flank cuts) and freezing (−20 ℃ for two months) on different quality parameters. Frying process produced a decrease of water content, an increase in lipid oxidation indicators, and an intense browning of nuggets surface. The use of flank up to a 75% of the total meat in the formula led to higher fat contents and higher polyunsaturated fatty acid proportions in fried nuggets. This made them more prone to get oxidized during the freezing storage and subsequent final frying. Nuggets with a higher proportion of flank also showed lower shear force values. However, nuggets with both formulations showed similar sensory acceptance. Freezing storage of lamb meat nuggets for two months increased the levels of lipid oxidation indicators, but again not to a level high enough to influence the sensory perception by consumers. So that, frozen nuggets from both formulations showed similar consumer acceptance to freshly produced ones with quite good scores (3.46–3.86 out of 5). Thus, low-value lamb cuts are suitable for being processed into highly acceptable prefried frozen lamb nuggets, which constitutes an opportunity for adding value to the whole lamb value chain.

Effect of muscle type and frozen storage on the quality parameters of Iberian restructured meat preparations

The main objective of this study was to evaluate the effect of muscle type and frozen storage on the quality of restructured meat preparations from undervalued Iberian muscle to make use of meat from a high-quality and natural pig production system. The effect of two muscle types (i.e. white-glycolytic (W) and red-oxidative (R)) and frozen storage (lasting 0, 30, 60 and 90 days) on quality characteristics were assessed. Significant differences were found between the W and R Iberian restructured preparations in most physicochemical and some colour, texture and sensory traits, and in the fatty acid profile and oxidative measurements, suggesting that the R muscles are more suitable; however, the microbial contamination should be reduced. Frozen storage reduced but did not eliminate the initial microbial contamination, and it enhanced some quality traits in the Iberian restructured preparations, i.e. increased a* values, cohesiveness and juiciness and decreased adhesiveness and pastiness, without negatively affecting any parameter. Thus, frozen Iberian restructured preparations are recommended to be commercialized. In addition, the implementation or revision of Hazard Analysis and Critical Control Point is recommended to reduce microbial contamination.

Effect of conventional and pressure frying on lipids and fatty acid composition of fried chicken and oil

Lipid class and fatty acid profile of pressure fried (PF) and conventionally fried (CF) chicken and medium of frying were evaluated. Depending on the frying cycle, neutral lipid (NL) content of PF chicken varied from 75-86% as compared to that of CF (84-90%). Similarly, glycolipid (GL) content varied from 11-21% in PF and from 9-12% in case of CF. Phospholipid (PL) was the least among lipid classes in both the products. The fresh frying medium (oil before frying cycle started), NL, GL and PL were 89, 10 and 0.33%, respectively. After the frying cycles were over, NL content of oil used for CF decreased to 82% and GL content increased from 10 to 17%. There was no significant difference (p ≥ 0.05) between the contents of lipid classes of oil used for PF or CF. Fried chicken and frying medium had higher concentration of linoleic acid and oleic acid irrespective of the frying cycle or frying method. PF chicken had moisture content in the range of 56-58% and total fat was 14% whereas in case of CF chicken it ranged from 49-52% and 18% respectively. TBA and FFA values of CF chicken and oil on repeated frying were higher (p ≤ 0.05) than PF. In comparison to conventional frying, pressure frying resulted in relatively tender and juicier product presumably due to better retention of moisture (p ≤ 0.05) and low oil uptake.

Effect of different cooking methods on lipid oxidation and formation of free cholesterol oxidation products (COPs) in Latissimus dorsi muscle of Iberian pigs

The aim of this work was to study the influence of different cooking methods (grilled (GR), fried (FP), microwave (MW) and roasted (RO)) on lipid oxidation and formation of free cholesterol oxidation products (COPs) of meat from Iberian pigs that have been fed on an intensive system. Moisture and total lipid content, TBARs, hexanal and COPs were measured in Latissimus dorsi muscle samples. Cooking did not produce changes in total lipid content in meat but induced significantly higher lipid oxidation (TBARs and hexanal values) (p<0.001) and cholesterol oxidation (COPs) (p<0.01). When the different cooking methods were studied, the grilled method was the least affected by lipid oxidation (TBARs and hexanal) compared to the others. There were no significant differences among different cooking methods on COPs values. The most abundant cholesterol oxides were both 7α-hydroxycholesterol and 7β-hydroxycholesterol in all groups studied.