Transcriptome profiling of longissimus thoracis muscles identifies highly connected differentially expressed genes in meat type sheep of India.

This study describes the muscle transcriptome profile of Bandur breed, a consumer favoured, meat type sheep of India. The transcriptome was compared to the less desirable, unregistered local sheep population, in order to understand the molecular factors related to muscle traits in Indian sheep breeds. Bandur sheep have tender muscles and higher backfat thickness than local sheep. The longissimus thoracis transcriptome profiles of Bandur and local sheep were obtained using RNA sequencing (RNA Seq). The animals were male, non-castrated, with uniform age and reared under similar environment, as well as management conditions. We could identify 568 significantly up-regulated and 538 significantly down-regulated genes in Bandur sheep (p≤0.05). Among these, 181 up-regulated and 142 down-regulated genes in Bandur sheep, with a fold change ≥1.5, were considered for further analysis. Significant Gene Ontology terms for the up-regulated dataset in Bandur sheep included transporter activity, substrate specific transmembrane, lipid and fatty acid binding. The down-regulated activities in Bandur sheep were mainly related to RNA degradation, regulation of ERK1 and ERK2 cascades and innate immune response. The MAPK signaling pathway, Adipocytokine signaling pathway and PPAR signaling pathway were enriched for Bandur sheep. The highly connected genes identified by network analysis were CNOT2, CNOT6, HSPB1, HSPA6, MAP3K14 and PPARD, which may be important regulators of energy metabolism, cellular stress and fatty acid metabolism in the skeletal muscles. These key genes affect the CCR4-NOT complex, PPAR and MAPK signaling pathways. The highly connected genes identified in this study, form interesting candidates for further research on muscle traits in Bandur sheep.

Carcass and meat quality characterization of indigenous and improved variety of chicken genotypes.

A study was conducted to examine four genotypes of chicken for their carcass and meat quality characteristics. From each genotype, 20 birds were slaughtered at their respective age of maturity. Breast and thigh muscles were evaluated for meat quality characteristics. Transport loss and carcass weight were highest in the white commercial broiler (WBR) and lowest in Aseel (ASL) and Indbro Aseel (ASR). Dressing percentage ranged between 66.41 and 72.56 and was not significantly different among genotypes. The yield of various cut-up parts for different genotypic birds was significantly different (P < 0.05). Highest percent yield for breast (29.15), thigh (15.57), drumstick (13.82) and wings (18.44) were observed in WBR, rainbow rooster (RR), ASR and rainbow rooster Plus (RRP), respectively. Giblet % was highest in RR and meat:bone ratio of thigh portion was highest in WBR. Higher ultimate pH was recorded for RR, RRP, and WBR, and higher water-holding capacity was detected in ASL and ASR. Further, bound water was higher in RR, RRP, and WBR, and free water was maximum in ASL and ASR. A significant (P < 0.05) higher shear force was observed in ASL and higher muscle fiber diameter in WBR. Cooking yield did not differ significantly among genotypes. The breast meat from ASL showed significantly (P < 0.05) higher redness value and WBR showed the lower redness. Further, ASL and ASR meats were darker and red in color than broiler meat. Meat from two indigenous birds (ASL and ASR) had significantly (P < 0.05) lower fat content compared to broilers and other crosses. ASL gave a slightly firmer meat as liked by consumers. The sensory evaluation showed breast meat from RR birds and ASL birds had better flavor scores than other birds. These results indicated that meat of indigenous chickens (ASL and ASR) has some unique features over commercial fast-growing birds that would increase their demand by consumers who prefer chewy, low-fat chicken meat.

Effect of vacuum packaging and pomegranate peel extract on quality aspects of ground goat meat and nuggets.

The effect of vacuum packaging and pomegranate peel extract on ground goat meat and cooked nuggets during refrigerated storage (4 ± 1 °C) was evaluated. Three different treatments evaluated were: I). Aerobic packaging (AP); II) Vacuum packaging (VP) and III). Vacuum packaging along with 1 % pomegranate peel extract (VP + PPE). Results of quality evaluation showed that VP and VP + PPE maintained a more stable colour than AP. In all treatments, a significant (P < 0.05) increase in hardness and gumminess of nuggets was observed during the storage. But, VP nuggets showed minimum changes in texture parameters. TBARS values were significantly (P < 0.05) lower in VP and VP + PPE than AP. In ground meat, VP reduced the TBARS by 27 % and PPE reduced the TBARS by 41 %. In nuggets, TBARS was decreased by 17 % and 40 % in VP and VP + PPE respectively. Total plate counts were significantly higher (>log 7) in AP than VP meat and nuggets. Thus VP and PPE have a synergistic antioxidant effect and VP extended the refrigerated shelf life of goat meat and nuggets.

Evaluation of quality characteristics of chicken meat emulsion/nuggets prepared by using different equipment.

Chicken meat emulsions prepared using food processor (FP), an indigenous meat cutter (MC) and bowl chopper (BC) were evaluated for physicochemical, texture and electron microscopic studies (SEM). Product yield, emulsion stability, hydration properties and gel strength (N) were significantly (P < 0.05) higher in BC. Total fluid release (TFR), water release (WR) and fat release (FR) was lowest in BC. Significantly (P < 0.05) higher lightness (L) in BC and redness (a) in FP emulsion were observed. Higher firmness, gumminess, chewiness and cohesiveness were observed in BC emulsion. SEM studies revealed a dense and compact protein matrix characteristic of heat induced protein gels. All micrographs showed structures that are compatible with fat globules, muscle fiber, meat protein matrix and heat induced gel/protein matrix. Sensory evaluation showed no significant difference between three treatments for colour, flavour, texture and acceptability scores. Thus, food processor and indigenously developed meat cutter found suitable for producing a stable chicken meat emulsion required for indigenous meat products.

Comparative antioxidant effect of BHT and water extracts of banana and sapodilla peels in raw poultry meat.

Antioxidant properties of banana (Musa paradisiaca) and Sapodilla/Chikoo (Manilkara zapota) peel extracts in chicken patties were evaluated. Four treatments viz., I. Control (meat + 2% salt), II.BHT (meat + 2% salt + 0.1% BHT), III. BPE (meat + 2% salt + 2% banana peel extract) and IV. SPE (meat + 2% salt + 2% sapodilla/chikoo peel extract) were compared for changes in colour and lipid oxidation during 8 days refrigerated storage (4 ± °C). The average phenolic content was 550.2 and 550.8 mg gallic acid equivalent per 10 g peel in BPE and SPE respectively. Free radical scavenging activity was 66.9 and 67.8% in BPE and SPE respectively. Banana peel extract had significantly (P < 0.05) higher reducing activity (1.6) as compared to sapodilla peel extract (0.91). During refrigerated storage period, all color parameters decreased significantly in all treatments. Observation on lipid oxidation showed a significantly (P < 0.05) higher TBARS values in control than other three treatments. The increase in TBARS from initial day of storage to last day of storage was highest in control (514.3%) as compared to BHT (387.7%), BPE (370.6%) and SPE (383.7%). Both synthetic antioxidants and natural extracts significantly decreased the TBARS. The average decrease in TBARS values during 8 days of storage was 56.8%, 38.3% and 37.2% values in BHT, BPE and SPE treatments respectively. Therefore, it was concluded that water extracts obtained from banana and sapodilla peels could be explored as natural antioxidants in poultry meat and meat products.

Antibacterial activity of aqueous extract of pomegranate peel against Pseudomonas stutzeri isolated from poultry meat.

In this study antibacterial activity of pomegranate peel (PPE) was evaluated against bacteria isolated from poultry meat. The bacteria were identified using 16S rRNA gene and DNA sequencing. Results of molecular characterization showed that the bacteria isolated were having 100% homology with the Pseudomonas stutzeri strain CTSP36 and further analysis showed that sample sequence clustered with the P. stutzeri strain CTSP36. Antibacterial activity of PPE was demonstrated by clear zone of inhibition in plates inoculated with extract. The diameter of inhibition zones were significantly (p < 0.05) higher in PPE as compared to standard antibiotic discs used (tetracycline, vancomycin and streptomycin). Results of broth dilution assay also revealed that PPE at 1%, 5% and 10% were effective in inhibiting bacterial growth in test plates. Further, a decrease in the growth of bacterial cells and a gradual decline in protein content of bacterial cells were also observed when bacterial culture was grown with different concentration of PPE along with a control. These results showed the potential application of pomegranate peel extract as antibacterial agent against P. stutzeri.

Comparative antioxidant effect of aqueous extracts of curry leaves, fenugreek leaves and butylated hydroxytoluene in raw chicken patties.

Antioxidant properties and use of aqueous extracts of curry leaves (Murraya koenigii) and fenugreek leaves (Trigonella foenum-graecum) as source of natural antioxidant in raw chicken meat were evaluated. Four treatments viz., I. Control (meat +2% salt), II.BHT (meat +2% salt +0.1% BHT), III. CLE (meat +2% salt +2% curry leaves extract) and IV. FLE (meat +2% salt +2% fenugreek leaves extract) were compared for lipid oxidation during eight days refrigerated storage. The average phenolic content was 59.2 and 52.8 mg/g gallic acid equivalent in CLE and FLE respectively. Free radical scavenging activity was 61.4 and 64.2% in CLE and FLE, respectively. CLE had significantly (P < 0.05) higher reducing activity (2.4) as compared to FLE (2.2). Observation on lipid oxidation showed a significant (p < 0.05) higher TBARS values in control patties than other patties containing BHT, CLE and FLE. Overall percent increase during storage period was highest in control followed by BHT, CLE and FLE. Both synthetic antioxidants and natural extracts significantly (p < 0.05) decreased the TBARS values. The average percent decrease in TBARS values during storage was 18, 25.5 and 27.5 in BHT, CLE and FLE treatments, respectively. Therefore, it was concluded that water extracts obtained from curry leaves and fenugreek leaves could be explored as natural antioxidants in poultry meat and meat products.

Effect of ammonium hydroxide on ultrastructure and tenderness of buffalo meat.

This study was conducted with an objective to improve the tenderness of tough buffalo meat using ammonium hydroxide. Buffalo meat chunks from Biceps femoris muscle were marinated with distilled water (control), 0.1%, 0.5% and 1.0% solution of ammonium hydroxide for 48 h at 4±1 °C and subjected to various physico-chemical analysis and ultrastructural studies. Ammonium hydroxide increased (P<0.05) the pH, water holding capacity (WHC), collagen solubility, total and salt soluble protein extractability and cooking yield. Reduction (P<0.05) in Warner-Bratzler shear force values were observed in all ammonium hydroxide treated samples compared to non-treated control. Electrophoretic pattern of muscle proteins exhibited reduction in the intensity and number of certain protein bands for 0.1% and 0.5% ammonium hydroxide treated samples compared to control. Scanning and transmission electron microscopy also revealed breakdown of endothelium layers surrounding muscle fibers and weakening of Z-discs respectively, in treated samples compared to controls. These results suggest that ammonium hydroxide might be used to tenderize tough buffalo meat.

Tenderizing effect of blade tenderizer and pomegranate fruit products in goat meat.

Toughness of goat meat is a major problem with regard to consumer acceptance. Keeping this in view a blade tenderizer was developed for tenderization of goat meat. Pomegranate fruit products were also explored for tenderization effect on goat meat. Tenderization of goat meat with pomegranate seed powder improved the textural properties marginally with slight adverse colour change and taste. Samples treated with PRP got lower score for colour in sensory evaluation and there was adverse effect on taste of treated meat. Blade tenderization and 4% PSP proved better for tenderization and were compared with control and 0.2% papain in goat meat chunks. The cooked samples treated with papain and blade incisions got better sensory scores and required lesser shear force compared to 4% PSP and control. Overall the papain treated meat was superior in terms sensory attributes followed by blade incision and PSP. The results suggested that the blade incisions can be used for tenderization of goat meat. Pomegranate seed powder maybe considered for mixing with other spices to marinate goat meat mainly for its beneficial effects.

The effect of salt, extract of kinnow and pomegranate fruit by-products on colour and oxidative stability of raw chicken patties during refrigerated storage.

Use of extracts of kinnow and pomegranate by-products as source of natural antioxidant in salted chicken patties during refrigerated storage was evaluated. Five treatments viz., I. Control (meat), II.MS (meat + 2%salt), III. KRP (meat + 2% salt + 2% kinnow-rind-powder extract), IV. PRP (meat + 2% salt + 2% pomegranate-rind-powder extract), and V. PSP (meat + 2% salt + 2% pomegranate seed powder extract). Results showed that salt significantly (P < 0.05) reduced lightness and yellowness but increased chroma and TBARS values. The average increase in TBARS was significantly (P < 0.05) higher in MS (114%) and Control (108%) but lower in KRP (90%), PRP (81%) and PSP (73%). Lipid oxidation (TBARS) in salted meat during the storage was significantly reduced (P < 0.05) by KRP (39%), PRP (43%) and PSP (68%). Thus it was observed that addition of 2% salt accelerated the TBARS formation but inclusion of extracts of pomegranate and kinnow fruit by-products effectively counteracted this effect. The overall antioxidant effect was in the order of PSP>PRP>KRP. Further a significant (P < 0.05) negative correlation between total phenolics contents and TBARS values was also observed. Therefore, it was concluded that extracts of these fruit by-products have potential to be used as natural antioxidants to minimize the oxidative problems in poultry meat products.

Anti-oxidant effect of extracts of kinnow rind, pomegranate rind and seed powders in cooked goat meat patties.

To overcome the disadvantages of using synthetic anti-oxidants in meat products, an investigation was carried out to evaluate the anti-oxidant effect of extracts of fruit by-products viz., kinnow rind powder (KRP), pomegranate rind powder (PRP) and pomegranate seed powder (PSP) in goat meat patties. Total phenolics content, DPPH radical scavenging activity and effect of these extracts on instrumental color, sensory attributes and TBARS values during storage (4+/-1 degrees C) of goat meat patties were evaluated. Results showed that these extracts are rich sources of phenolic compounds having free radical scavenging activity. Hunter Lab L value significantly (P<0.05) lowered in PRP followed by PSP and KRP patties. Sensory evaluation indicated no significant differences among patties. Further, a significant (P<0.5) reduction in TBARS values (lipid oxidation) during storage of goat meat patties was observed in PRP, PSP and KRP as compared to control patties. Average TBARS values (mg/kg meat) during refrigerated storage (4+/-1 degrees C) were significantly lower in PRP, followed by PSP and KRP as compared to control. The overall anti-oxidant effect was in the order of PRP>PSP>KRP. It was concluded that extracts of above fruits by-product powders have potential to be used as natural anti-oxidants in meat products.

Effect of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat during refrigerated storage.

Effects of salt, kinnow and pomegranate fruit by-product powders on color and oxidative stability of raw ground goat meat stored at 4+/-1 degrees C was evaluated. Five treatments evaluated include: control (only meat), MS (meat+2% salt), KRP (meat+2% salt+2% kinnow rind powder), PRP (meat+2% salt+2% pomegranate rind powder) and PSP (meat+2% salt+2% pomegranate seed powder). Addition of salt resulted in reduction of redness scores. Lightness increased in control and unchanged in others during storage. Redness scores declined and yellowness showed inconsistent changes during storage. Thiobarbituric acid reactive substances (TBARS) values were higher (P<0.05) in MS followed by control and KRP samples compared to PRP and PSP samples throughout storage. The PSP treated samples showed lowest TBARS values than others. Percent reduction of TBARS values was highest in PSP (443%) followed by PRP (227%) and KRP (123%). Salt accelerated the TBARS formation and by-products of kinnow and pomegranate fruits counteracted this effect. The overall antioxidant effect was in the order of PSP>PRP>KRP>control>MS. Therefore, these powders have potential to be used as natural antioxidants to minimize the auto-oxidation and salt induced lipid oxidation in raw ground goat meat.