This paper describes the influence of different factors on toughness of beef semitendinosus (ST) by means of low temperature-long time cooking with single-stage (60 °C, 65 °C, 70 °C, and 75 °C for 6 h and 12 h) and two-stage sous-vide procedure (45 + 60 °C, 45 + 65 °C, 45 + 70 °C, and 45 + 75 °C; 49 + 60 °C, 49 + 65 °C, 49 + 70 °C, and 49 + 75 °C for 3 h at the first temperature, and either 3 or 9 h at the second temperature). Reduced toughness of ST beef steak muscle could be attained in 6 h at 60 °C and 45 + 60 °C were due from the minimum shrinkage of sarcomere as well as lower perimysial thickness, cooking loss, and elastic modulus. Collagen solubility showed a positive correlation to the toughness values. The relationship between proteolytic activity and shear force can be seen after 12 h of cooking duration. For the other quality attributes, two stepped cooking temperature-time combination seems to be more effective in preserving the redness values and water content than a single-stage sous-vide method.
In the current study, the effect on packaged beef fillets (1 × 5 × 8 cm) of using active chitosan film (1%) was investigated. The fillets were stored at 4 °C for 12 days, and the film contained ɛ-polylysine (ɛ-PL) (0.3, 0.6, and 0.9% w/w). Chemical, microbiological, sensory properties, and quality indices of the fillets were investigated. Added to these factors was an assessment of the influence of ɛ-polylysine incorporation on the optical, structural, barrier, and mechanical specifications (elongation at break and tensile strength) of chitosan films. Based on the findings, a significant difference among the corresponding values to thickness, color, water vapor permeability (WVP), and mechanical specifications between the treated films by ɛ-PL and untreated films were noted. In addition, higher values of thickness and tensile strength were correlated with ɛ-PL added active chitosan films while compared with control samples. Additionally, no significant differences regarding the proximate composition (including protein, moisture, and fat) among beef fillet samples were observed. In this regard, due to significantly lower levels of pH, TVB-N, and TBARS ɛ-PL in enriched films, this technique demonstrated some protective effects on beef fillets. Another observation was that lower levels of the total viable count, coliform, mold, yeasts, and higher sensory properties were significantly associated with samples with added ɛ-PL (0.9%). Therefore, adding ɛ-PL into chitosan films could be introduced as an effective technique to extend the shelf life of beef fillets and maintain their quality indices during refrigerated storage.
The effects of dietary supplementation of different parts of Andrographis paniculata on fatty acids, lipid oxidation, microbiota and quality attributes of Longissimus thoracis et lumborum (LTL) muscle in goats were assessed. Twenty four, entire Boer bucks (4 months old; 20.18 ± 0.19 kg BW) were randomly allotted to either a basal diet without additive (AP0), a basal diet + 1.5% Andrographis paniculata leaves (APL) or a basal diet + 1.5% Andrographis paniculata whole plant (APW). The bucks were fed the diets for 100 d and slaughtered. The LTL muscle was subjected to a 7 d chill storage. The AP0 meat had higher (p meat. The concentrations of total C18:1trans, total CLA, C18:1n-9, C18:2n-6, C18:3n-3 and C20:5n-3 were higher (p meat than the AP0 meat. Diets had no effect (p > .05) on muscle glycogen, pH, drip loss, chemical composition and lactic acid bacteria count. Cooking loss, shear force, and TBARS values were lower (p meat compared with AP0 (26.49%, 1.13 kg, 0.23 mg MDA/kg) meat. Meat redness was higher (p meat were higher (p meat. Total viable counts and populations of Pseudomonas spp, Escherichia coli and Enterobacteriacea were higher (p meat than in APL and APW meat. The APL exhibited higher (p
Replacement of beef by buffalo and vice versa is frequent in global markets, but their authentication is challenging in processed foods due to the fragmentation of most biomarkers including DNA. The shortening of target sequences through use of two target sites might ameliorate assay reliability because it is highly unlikely that both targets will be lost during food processing. For the first time, we report a tetraplex polymerase chain reaction (PCR) assay targeting two different DNA regions in beef (106 and 120-bp) and buffalo (90 and 138-bp) mitochondrial genes to discriminate beef and buffalo in processed foods. All targets were stable under boiling, autoclaving and microwave cooking conditions. A survey in Malaysian markets revealed 71% beef curries contained buffalo but there was no buffalo in beef burgers. The assay detected down to 0.01ng DNA and 1% meat in admixed and burger products.