Chemical composition characteristics of the longissimus and semimembranosus muscles for pigs from New Zealand and Singapore

Consumer eating quality and physicochemical traits of pork Longissimus and Semimembranosus differed between genetic lines

Pork eating quality is affected by various factors. In this study, Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM) muscles from seven genetic lines (PM-LR - Pure maternal, Landrace-type; PM-LW - Pure maternal, Large White-type; PM-D - Pure maternal, Duroc-type; PT-D - Pure terminal, Duroc-type; PT-LW - Pure terminal, Large White-type; PT-LR - Pure Terminal, Landrace-type; Comp-P × LW × D - Composite Terminal - Pietran × Large white × Duroc) were analyzed for pH, intramuscular fat (IMF) content, and collagen content and solubility. A consumer sensory test using check-all-that-apply (CATA) and biometric approaches was also conducted. The results showed that the IMF content of line PM-D was the highest (P = 0.004), while line PT-LW received the highest score in tenderness, liking of flavor, purchase intent, and quality grading (P < 0.05). Line PM-LR and PT-LR showed the lowest IMF content and were least preferred by consumers. Compared to LTL, SM showed higher pH, collagen solubility, and sensory scores in tenderness, juiciness, liking of flavor, and overall liking (P < 0.05). Different muscles and lines were associated with different CATA terms but not with differences in consumer emotional responses. pH positively influenced tenderness, juiciness, and overall liking (P < 0.05), but IMF and collagen had little effect. The flavor was the most important sensory attribute contributing to overall liking, followed by tenderness. Genetic line and muscle affected pork chemical properties and eating quality. The findings are important for the Australian pork industry to improve the eating quality of their products.

Genetic lines influenced the texture, collagen and intramuscular fat of pork longissimus and semimembranosus

The effects of genetic lines (PM-LR - Pure maternal, Landrace-type; PM-LW - Pure maternal, Large White-type; PM-D - Pure maternal, Duroc-type; SynT-LWLR - Synthetic terminal, Large white and Landrace-type; PT-D - Pure terminal, Duroc-type; and PT-LW - Pure terminal, Large White-type) on carcass traits and pork quality, including cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis (TPA), collagen content and solubility and intramuscular fat (IMF) content of Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM), were investigated. The results showed that all terminal lines had lower backfat thickness than maternal lines, but muscles from line SynT-LWLR had the highest hardness and cohesiveness and the lowest IMF content. The SM showed higher hardness, adhesiveness, springiness, chewiness, collagen, and IMF content but lower WBSF and collagen solubility than LTL. Collagen and IMF content affected WBSF and TPA parameters across both muscles and in LTL alone. Significant relationships between collagen content and texture parameters were found in line PT-D. Genetic lines and muscles affect the contribution of collagen and IMF to pork texture.

Impact of the Addition of Tenebrio molitor and Hermetia illucens on the Physicochemical and Sensory Quality of Cooked Meat Products

The use of proteins from insects, plants, microalgae, fungi or bacteria as an alternative to proteins of animal origin such as meat, fish, eggs or milk can meet the worldwide protein demand in the future. As the consumption of whole insects might be problematic or unacceptable for many consumers, especially in European countries, the use of homogenized insects or protein extracts from insects for the production of products might be a possibility to overcome general acceptability problems. However, the quality criteria of these products have to be comparable with consumers' expectations with regard to known products. Therefore, in the present study, we produced a meat product, replaced 10% and 20% of the pork with homogenized larvae of Tenebrio molitor and Hermetia illucens, and determined different physicochemical and sensory parameters at production and during modified atmosphere storage for 21 days. Additionally, the alteration of different bacteria species during this storage was analyzed in challenge tests. After production, the addition of insects resulted in higher cooking losses and pH values in the products with 20% insects, higher pH and yellowness, lower lightness, protein and hardness results in the Hermetia products, as well as higher yellowness and lower protein and hardness values in the cooked meat products with Tenebrio molitor. During modified atmosphere storage, the color differences principally remained, whereas the concentrations of inoculated Bacillus cereus, Listeria monocytogenes and Escherichia coli were not influenced by the addition of insects to the cooked meat products. The sensory results of the insect products, especially at higher concentrations and with Hermetia illucens, worsened during modified atmosphere storage. The addition of homogenized insect larvae, especially at higher concentrations and particularly of Hermetia illucens, influences different physicochemical and sensory parameters of the cooked meat products.

Characterization of flavor volatile compounds in industrial stir-frying mutton sao zi by GC-MS, E-nose, and physicochemical analysis

This study aims to investigate the flavor changes of industrial stir-frying mutton sao zi, a mutton product popular in the northwest of China, at different stir-frying stages. Electronic nose (E-nose) was used to recognize mutton sao zi odors at different processing time points, and the individual volatile compounds were further identified by the solid-phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). A total of 105 volatile compounds were detected by GC-MS, of which 51 were major volatile compounds. Additionally, GC-MS and E-nose data of the samples were also correlated with the fatty acids, crude composition (moisture, fat, protein), and amino acids. The stir-frying time and temperature may be the critical contributors to different flavors of industrial stir-frying mutton sao zi. The signal intensities of W1S, W1W, W2S, W2W, and W3S sensors positively correlate with protein, fat, and 18 amino acids, but negatively with SFA and moisture. Hence, this study explored the flavor changes of industrial stir-frying mutton sao zi by E-nose and SPME-GC-MS for the first time, providing an insight into the industrial production and flavor control stir-frying machine of stir-frying mutton products with household flavor.

A comparison of physicochemical characteristics, texture, and structure of meat analogue and meats

BACKGROUND

The continuous increase of global consumer's dietary behaviors towards reducing meat consumption due to health benefits, ecological, ethical, and social aspects. Texturized vegetable protein (TVP) transformed from plant protein-based ingredient can impart fibrous structure like muscle meat. However, there is limited information on a comparison of product properties of TVP and meats. In this study, the comparison of physicochemical properties, texture, and structure of TVP and different types of meats (beef, pork, and chicken) were investigated.

RESULTS

The nitrogen solubility and integrity index, chewiness and cutting strength of TVP were similar to that of the chicken sample compared to other meats. However, water absorption capacity of TVP (2173.84 g kg^-1 ) was significantly higher than all meat samples (1095.37 to 1653.52 g kg^-1 ). The color and amino acids of TVP were different from meat samples due to the difference in protein types. TVP showed a fibrous structure with non-uniform air cells.

CONCLUSION

The study demonstrated that some textural and chemical characteristics of texturized vegetable protein under intermediate moisture extrusion exhibited the most similarity to chicken meat. © 2018 Society of Chemical Industry.

Characteristics of selected pork muscles 45 min and 24 h post mortem

The muscles of the pork topside – musculus adductor (AD) and m. semimembranosus (SM), and of the silverside – m. biceps femoris (BF) and m. semitendinosus (ST) were analysed and their properties compared with the m. longissimus thoracis (LT) and m. supraspinatus (SS) muscles. Colour (CIE L*a*b*), D/L-lactic acid content, and pH values were measured 45 min and 24 h post mortem. The basic chemical composition of muscles was analysed 24 h after slaughtering. A significant correlation (r = -0.61, P < 0.001) was found between the pH values and the level of lactic acid 45 min post mortem, though not 24 h after slaughter (r = -0.25, P > 0.05). The results confirmed that a direct comparison cannot be made between the fall in pH values in meat and the increase in the level of lactic acid. The lightness L* 24 h post mortem was higher (P < 0.05) in AD, BF, ST and LT muscles than those in samples measured 45 min after slaughter. The toughest muscle was biceps femoris, with a mean value of shear force of 90.5 N. The differences in shear force between the individual analysed muscles were significant (P < 0.05). There were significant differences in the intramuscular fat content between the topside and silverside muscles (P < 0.05). The results of the present study are of value to meat producers who might intend to substitute these parts of the leg with one another during the production, particularly in the case of whole-muscle meat products.

Carcass lean-yield effects on the fatty acid and amino acid composition of Duroc pork and its technological quality after vacuum-aging

Eighty purebred Duroc castrated male pigs slaughtered at 210 days of age were used to evaluate the effect of lean yield (European Union carcass grading based on lean content; or R, O and P classes) on the fatty acid and amino acid composition of raw pork (Day 1 post-mortem), and technological meat quality after vacuum aging up to 4, 6 and 8 days. A strong relationship between slaughter weight and carcass lean-yield was observed. Carcasses graded as having a lower lean yield were fatter with higher intramuscular fat concentration, and differences in proportions of fatty acids with increased monounsaturated fatty acid and decreased polyunsaturated fatty acid percentage, but without adverse effect on ultimate pH, drip loss or colour attributes. There were no effects of carcass lean-yield on amino acid composition of raw pork, with valine being the limiting amino acid relative to lysine by ~30–35%. Vacuum aging did not reduce the shear force of raw pork, which may not be indicative of cooked pork response. The lipid oxidation had an inverse relationship with the polyunsaturated fatty acid content of each pork class, and it did not increase due to vacuum aging up to 8 days. Meat fatness did not affect its amino acid balance and technological quality (colour, drip loss, shear force and lipid stability) but modified intramuscular fat composition.

Comparison of objective measures of pork colour traits during ageing of the longissimus muscle from pigs housed organically and conventionally

Pigs raised conventionally (n = 56) and indoors organically (n = 47) from different three-way crossbred genotypes were used to assess the capacity of pork colour attributes during ageing to discriminate between two methods of rearing pigs. Instrumental colour characteristics were measured on L. thoracis muscle from day 1 to 7 of storage, and the relative contents of metmyoglobin (MMb) and oxymyoglobin (MbO2) were estimated. The yellowness and chroma indices were lower in conventional than organic pork at all sampling times except on day 3 of storage. Lightness and hue angle were lower, whereas redness index was greater, in conventional than organic pork during all days of storage. Using MMb rather than MbO2 could be useful to highlight myoglobin oxidation in pork meat because it was weakly correlated with the measured CIELab colour attributes. Despite the differences in instrumental colour attributes, discrimination between conventional and organic (not free-ranging) pig husbandry was not possible. However, 3 days of storage combined the best colour (low hue angle and high redness index) and haeminic pigment balance (low MMb and high MbO2).

Characterization of Longissimus thoracis, Semitendinosus and Masseter muscles and relationships with technological quality in pigs. 2. Composition of muscles

The composition of three porcine muscles (Longissimus thoracis: LT, Semitendinosus: ST, Masseter: MS) was characterized and its link with muscle quality was evaluated. The LT muscle had a higher content of tyrosine, tryptophan, and carbohydrates and a lower content of vitamin E and haem iron than the MS muscle, while the ST had similar composition to MS but a lower content of haem iron. Large differences between muscles were observed in relative amounts of most of the major fatty acids. The LT muscle had higher saturated fatty acids (SFA) and n-6:n-3 fatty acid ratio, and lower polyunsaturated fatty acids (PUFA), PUFA:SFA ratio, unsaturation index and average fatty acid chain length than the ST and MS muscles. Muscle pH, redness and chroma were positively correlated with vitamin E and unsaturated lipids and negatively correlated with tyrosine, tryptophan, carbohydrates and saturated lipids, whereas muscle lightness and expressible juice showed similar correlations but an opposite sign with these variables.

Effect of gender (barrows vs. females) on carcass traits and meat quality of Celta pig reared outdoors

BACKGROUND

Today, the Celta is the unique indigenous pig breed of Galicia (northwest Spain), included in the Official Catalogue of Breeds of Spain as being in danger of extinction. The objective of this study was to estimate the effect of gender (barrows vs. female) on carcass traits and meat quality of Celta pig reared outdoors. The differences in carcass and meat quality between castrated barrows and gilts (n = 20), reared outdoors and slaughtered at a live weight of 140 kg, were determined.

RESULTS

The mean carcass weight was 108 kg and killing out percentage and chilling losses did not differ (P > 0.05) between genders, with a mean value of 78.2% and 2.68%, respectively. There were no statistical differences in the morphometric parameters between genders except for the leg length (LL) (P < 0.01), and hand length (HL) and ham length (Hml) (P < 0.001), which were greater in barrows. Gender affected significantly pH (5.67 vs. 5.55; P < 0.05) and moisture content (73.2% vs. 72.0%; P < 0.05), while intramuscular fat (IMF) did not differ significantly between genders (2.12% vs. 1.67%, P > 0.05) for barrows and females, respectively. No significant effect (P > 0.05) on parameters measured by Warner-Braztler (WB) test (shear force, firmness and total work of cut) was found, whereas textural profile analysis showed significant differences for all traits determined due to gender effect. Sensory evaluation of longissimus dorsi (LD) samples showed significant differences between genders in odour and taste traits. Finally, there were no significant differences (P > 0.05) in any amino acid concentrations between genders.

CONCLUSION

Values for carcass parameters indicated that Celta pigs produced very similar carcasses to those obtained from other rustic pigs. The percentage of 'noble' cuts relative to carcass weight was higher in barrows than in females. Finally, gender appeared to have little effect on the colour, textural organoleptic traits or amino acid profile of this breed of pig.

Dietary supplementation with carnosine improves antioxidant capacity and meat quality of finishing pigs

This study was conducted to determine the effect of dietary carnosine (β-alanyl-L-histidine) supplementation on antioxidant capacity and meat quality of pigs. 72 pigs approximately 60 kg were fed a corn- and soybean meal-based diet supplemented with 0, 25, 50 or 100 mg carnosine per kg diet for 8 weeks. Carnosine supplementation did not affect growth performance and carcass traits of pigs. However, the addition of 100 mg carnosine per kg diet increased pH value of muscle at 45 min, 24 h and 48 h postmortem. It also decreased drip loss at 48 h postmortem and increased redness value of muscle at 45 min postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet enhanced glycogen concentration and Ca-ATPase activity at 24 and 48 h postmortem, and reduced malondialdehyde and carbonyl protein complexes concentrations in muscle at 24 h postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet increased glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities in plasma, liver or muscle, as well as SOD and GSH-Px genes expression in muscle (p < 0.05). Taken together, these findings indicate that carnosine supplementation improves antioxidant capacity and meat quality of pigs.