Technological characteristics of pre- and post-rigor deboned beef mixtures from Holstein steers and quality attributes of cooked beef sausage

Pre-rigor salting improves gel strength and water-holding of surimi gel made from snakehead fish (Channa argus): The role of protein oxidation

The purpose of this study was to determine the effect of pre-rigor salting on the quality characteristics of surimi gels prepared from snakehead fish muscle. Pre-rigor and post-rigor muscle were mixed with 0.3% or 3% NaCl (w/w) and made into surimi gels, respectively. Results showed that pre-rigor muscle had a higher content of ATP, longer sarcomere, higher pH and greater protein solubility. Metabolic profile suggested that pre-rigor muscle had higher content (a 28-fold increase) of antioxidants such as butyryl-l-carnitine. Transmission electron microscopy showed more damage of mitochondria in post-rigor muscle. Surimi paste from pre-rigor meat chopped with 3% NaCl generally showed greater radical scavenging ability and had higher content of free sulfhydryl. Surimi gel made from pre-rigor muscle salted with 3% NaCl showed a larger gel strength (3.18 kg*mm vs. 2.22 kg*mm) and better water-holding (86% vs. 80%) than that of post-rigor group. Based on these findings, we hypothesized that: In addition to other factors such as pH, degree of denaturation, etc., less protein oxidation in pre-rigor salted surimi also contributes to the improved gel properties.

Influence of Long-Term Freezing of Carcasses in Pre- and Post-Rigor Mortis Stages on the Technological and Nutritional Parameters of the Longissimus lumborum Muscle of Botucatu Rabbits

The aim was to assess the impact of long-term storage on the quality of Botucatu rabbit meat frozen in pre- and post-rigor stages. The stability of the technological and nutritional parameters of Longissimus lumborum (LL) muscle was analyzed over 12 months. In the post-rigor phase, the dorsal LL surface showed a higher level (p < 0.05) of redness and saturation, while the ventral surface showed a higher level (p < 0.05) of yellowness compared to the pre-rigor LL muscle. During storage, the redness and saturation in the LL muscle decreased (p < 0.05), while the yellowness increased (p < 0.05) on both dorsal and ventral surfaces. In the first six months, the pre-rigor meat had a higher pH (p < 0.05) compared to the post-rigor meat. The fresh meat showed higher (p < 0.05) shear force values in the post-rigor stage. Over the 12-month study period, the lipid oxidation, myofibrillar fragmentation index, gross energy, and levels of protein, fat, and carbohydrates increased (p < 0.05), while the shear force, mineral content, and moisture decreased (p < 0.05). Thus, rigor mortis affects meat color in Botucatu rabbits. Fresh meat in the pre-rigor stage is softer, moister, and less acidic than post-rigor meat after 24 h of chilling. Long-term freezing enhances tenderness, regardless of the rigor phase at freezing, preserving its physical, chemical, and nutritional quality, with minor changes in color, lipid oxidation, and chemical composition.

Shelf-Stability of Kiln- and Liquid-Smoked Inulin-Fortified Emulsion-Type Pangasius Mince Sausage at Refrigerated Temperature

The objective of this study was to investigate the effects of the kiln (SK-S) and liquid smoking (LS-S) processes on the quality of inulin-fortified emulsion-type Pangasius mince sausages. The moisture content during the storage significantly (p < 0.05) decreased in C-S (control) sausages and increased (p < 0.05) in SK-S and LS-S sausages. The protein content decreased (p < 0.05) in C-S, SK-S, and LS-S throughout the storage period. Initially, among the three processed sausages, LS-S showed a lower pH value, and as the days of storage progressed, all the treatments exhibited a declining trend (p < 0.05). A significant (p < 0.05) increase in the PV was observed in all the sausages during the storage days at 5 ± 1 °C, but the intensity of the increase was lower in SK-S and LS-S. The total viable count of C-S and SK-S sausages reached the limit of acceptability (6 log10cfu g-1) on the 20th day and on the 24th day of storage. The electrophoretic protein pattern of LS-S samples exhibited retention of all bands, indicating the lower proteolysis of MHC, actin, and troponin T in comparison with other treatments. The hardness (p < 0.05) and cohesiveness (p > 0.05) values of both SK-S and LS-S reduced as the storage days progressed. The present study indicates that the emulsion-type Pangasius sausages incorporated with inulin powder (2%) exposed to kiln smoking and commercial liquid smoking retained good-to-better sensory attributes up to day 16 (C-S) and day 20 (SK-S and LS-S) under refrigerated storage at 5 ± 1 °C in low-density vacuum polyethylene (LDPE) pouches.

Characteristics of pork emulsion gel manufactured with hot-boned pork and winter mushroom powder without phosphate

This study investigated the physicochemical characteristics of pork emulsion gels manufactured from hot-boned (HB) pork and winter mushroom powder in the absence of phosphate. It was found that compared to cold-boned (CB) pork, HB pork had a higher pH and exhibited a higher myofibrillar protein solubility with a lower actomyosin content (P < 0.05). Four types of pork gels were prepared, namely CB pork without phosphate, CB pork with phosphate (CBP), HB pork without phosphate, and HB pork with winter mushroom powder but without phosphate (HBW). The total exuded fluid was comparable for the CBP and HBW gels on all storage days. In addition, the HB and HBW gels had similar springiness and cohesiveness properties to the CBP gel (P > 0.05). These results indicate that the quality of pork gels manufactured in the absence of phosphate can be improved by the use of HB pork and with the incorporation of winter mushroom powder.

Effects of chilling rate on progression of rigor mortis in postmortem lamb meat

This work investigated the effects of chilling rate on the progression of rigor mortis and explored possible mechanisms. Silverside from 18 lamb carcasses was assigned to control group (1.94 °C/h), very fast chilling-I group (VFC-I, 12.19 °C/h) and VFC-II group (15.10 °C/h). The shear force, myofibril fragmentation index (MFI), actomyosin ATPase activity, protein degradation and actomyosin dissociation were determined. There was no increase in the shear force in VFC-II group. The activation of actomyosin ATPase at 2-4 h postmortem in VFC-II group resulted in super-contracted sarcomeres and an increase in MFI. The degradation of μ-calpain, troponin T and desmin in VFC-II group was higher than that in control group from 6 to 24 h postmortem. These results suggested that rigor mortis was influenced which resulted in decreased shear force at a chilling rate of 15.10 °C/h by activating actomyosin ATPase and μ-calpain at early postmortem and promoted actomyosin dissociation.

Effect of Postmortem Phases on Lamb Meat Quality: A Physicochemical, Microstructural and Water Mobility Approach

To investigate the effect of postmortem phases on lamb meat quality, the physicochemical quality, microstructure and water mobility of oyster cut, short loin, knuckle and silverside muscles from Small-Tail Han sheep were evaluated in the pre-rigor, rigor mortis and post-rigor phases. Pre-rigor lamb meat had higher pH and water holding capacity (WHC), whereas lower CIE L*, b*, hue angle values than rigor mortis and post-rigor meat (p<0.05). The Warner-Bratzler shear force (WBSF) values were higher in rigor mortis short loin and silverside than their pre-rigor and post-rigor counterparts, pre-rigor short loin had lower WBSF value than its post-rigor counterpart (p<0.05). Muscle fibers shrank laterally and longitudinally during the onset of rigor mortis. Rigor mortis and post-rigor lamb meat exhibited wide I-bands, dark A-bands, short sarcomeres and large inter-myofibrillar spaces. The shift of immobilized water to free water and repulsion from the intra-myofibrillar space to the extracellular space result in the increase of water loss in rigor mortis and post-rigor lamb meat. The results of the principal component analysis (PCA) indicated that rigor mortis and post-rigor lamb meat had similar quality properties but different from pre-rigor lamb meat. In conclusion, the lamb meat in the pre-rigor phase had good tenderness, color and WHC. The results of this research could provide some theoretical references for lamb meat production and processing.

Effect of pre- and post-rigor on texture, flavor, heterocyclic aromatic amines and sensory evaluation of roasted lamb

This study investigated the variation in texture, flavor, heterocyclic aromatic amines (HAAs) and sensory evaluation of pre- and post-rigor roasted lamb. Topside muscles were collected from twenty-eight lamb carcasses at 1 h, 6 h, 12 h, 1 d, 3 d, 5 d and 7 d postmortem and then roasted at 180 °C for 8 min. According to the pH and shear force (SF) values, the lamb muscles at 1-12 h, 1 d and 3-7 days postmortem were considered to be in the phases of pre-rigor, rigor and post-rigor, respectively. Pre-rigor roasted lamb showed a lower roasting loss, while the post-rigor roasted lamb showed a lower SF value. Higher concentrations of total volatile compounds were found at 3 days postmortem. The total contents of HAAs were significantly lower in pre-rigor roasted lamb compared to the post-rigor roasted lamb (P < .05). Overall, it was concluded that both pre- and post-rigor "roasted lamb" have their own special properties.

Evaluation of NaCl and KCl Salting Effects on Technological Properties of Pre- and Post-Rigor Chicken Breasts at Various Ionic Strengths

The objective of this study is to evaluate the effects of NaCl and KCl salting on technological properties of pre- and post-rigor chicken breasts at various ionic strengths. The following factorial arrangement was used: 2 salt types (NaCl and KCl) × 2 rigor statuses (pre- and post-rigor) × 4 ionic strengths (0.086, 0.171, 0.257, and 0.342). Hot-boned and ground chicken breasts were salted within 30 min postmortem after slaughter (pre-rigor salting) or 24 h postmortem (post-rigor salting) with varying concentrations of NaCl (0.50%, 1.00%, 1.50%, and 2.00%) or KCl (0.64%, 1.28%, 1.91%, and 2.55%) corresponding to the four ionic strengths. KCl caused higher pH value in salted chicken breasts than NaCl (p < 0.05). However, KCl decreased total and myofibrillar protein solubilities in post-rigor salted chicken breasts compared to NaCl (p < 0.05), but those were similar to pre-rigor chicken breasts, regardless of the salt type (p > 0.05). Different salt types had no significant impact on cooking loss and textural properties. This study shows that NaCl and KCl had similar effects on technological properties at the same ionic strength (within 0.342), but the use of KCl may have the possibility to decrease protein solubility, depending on rigor status of raw meat at the different salting time.

Consumer Acceptability and Demand for Cooked Beef Sausage Formulated With Pre- and Post-Rigor Deboned Beef

The objective of this study was to compare consumer acceptability and demand between pre- and post-rigor cooked beef sausage. Consumers (N = 100) evaluated the appearance, aroma, flavor, texture, and overall acceptability on a 9-point hedonic scale and formulated an independent bid for each product. Consumers preferred the aroma and flavor of pre-rigor sausage to those of post-rigor sausage (P = 0.008 and 0.029, respectively). This resulted in a greater overall acceptability of pre-rigor sausage than that of post-rigor sausage (P = 0.011). Cluster analysis revealed that 45 consumers in clusters 3 and 4 led to such greater acceptability. Average predicted unit-demand for the experiment was 1.59 kg (3.50 lbs)/(USD)$ greater for pre-rigor than for post-rigor sausage (P ≤ 0.001). Overall, the results indicated that pre-rigor processing yielded sausage with greater consumer acceptability and demand.

Relevant Aspects of Clostridium estertheticum as a Specific Spoilage Organism of Vacuum-Packed Meat

Clostridium estertheticum is a psychrotolerant, gram-positive, motile, anaerobic, spore-forming, rod-shaped bacteria that causes blown pack spoilage (BPS). Spoilage occurs in vacuum-packed meat without temperature abuse. Having been reported in the last 30 years in several countries, BPS by Cl. estertheticum is a major issue around the world and presents a huge economic impact on the meat industry. Despite being an important spoilage microorganism, studies on Cl. estertheticum are challenged by numerous aspects. These include, lack or poor growth in laboratory media, long culturing periods, and unpredictable isolation on the media. These factors hamper the detection of Cl. estertheticum before occurrence of BPS, which further undermines efforts to prevent the occurrence of BPS. Nevertheless, considerable developments have taken place with regard to culture-independent methods. Although information on Cl. estertheticum is available, it is limited and remains highly fragmented. Therefore, this review collates the available information and discusses relevant aspects of Cl. estertheticum as a specific spoilage organism of BPS in vacuum-packed meat.