Understanding the effect of meat electrical conductivity on Pulsed Electric Field (PEF) process parameters and the ability of PEF to enhance the quality and shorten sous vide processing for beef short ribs

The aim of this research was to investigate how the electrical conductivity of short ribs affected Pulsed Electric Field (PEF) process parameters and the ability of PEF to enhance their quality and reduce sous vide (SV) processing time. Short ribs with different range of electrical conductivity (3-6, 6-9, and 9-12 mS/cm) values were treated using input voltage of 10 kV, pulse width of 20 µs, pulse frequency of 50 Hz and pulse number, of either 1600 (low intensity PEF/LPEF) or 5200 (high intensity PEF/HPEF), followed by SV processing at 60 °C for either 24 or 36 h. The quality parameters assessed were cooking loss (%), Texture Profile Analysis (TPA) parameters, and Commission Internationale d'Eclairage (CIE) L*a*b* colour parameters. There was a variation in electrical conductivity of short ribs according to the position of the bone in the short rib, which demonstrated good congruence with the distribution of fat and connective tissue. SV processing with or without PEF pre-treatment did not have a significant effect (p > 0.05) on cooking loss or CIE L*a*b* colour parameters. Short ribs with a medium conductivity (6-9 mS/cm) had a significantly lower hardness after high intensity PEF followed by SV for 24 h, whilst short ribs with an average conductivity of 3-6 and 9-12 mS/cm required longer SV time (up to 36 h) and had a significantly lower hardness compared to non PEF pre-treated samples. TPA values of short ribs treated with the same PEF intensity and SV processing parameters were comparable regardless of the short ribs initial electrical conductivity, which indicates that PEF treatment could ameliorate the biological electrochemical variability inherent to short ribs and PEF could be the potential tool to decrease their SV processing time and enhance their tenderness.

Physicochemical characteristics and textural parameters of restructured pork steaks hydrolysed with bromelain

Enzymatic tenderisation including bromelain enhances underused cuts of meat in emerged restructuring technology. Physicochemical and textural characteristics of restructured pork steak hydrolysed with bromelain for masticatory dysfunction people were evaluated. Restructured pork steak treated with bromelain at 0.05 and 0.1% (w/w) was hydrolysed at 50 °C for 0, 3, 6, 9 and 12 min. The cooking losses of 0.05% (w/w) bromelain for 0, 3 and 6 min were lower than 0.1% (w/w) bromelain samples. The ΔE increased after increasing the enzyme concentration and hydrolysis time. Bromelain-treated samples at higher concentrations showed lower WBSF, KSF and TPA parameters, but cohesiveness of 0.05% (w/w) had higher than 0.1% (w/w) bromelain samples. Total protein, sarcoplasmic protein solubility, TCA-soluble peptide, total collagen and soluble collagen contents were the highest in 0.1% (w/w) bromelain-treated samples for 12 min (P < 0.05). According to SDS-PAGE and SEM, various proteins in the enzyme-treated samples were degraded.

Biochemical and technological characteristics of wooden breast chicken fillets and their consumer acceptance

The wooden breast (WB) has caused great damages to meat producing industries, being its etiology still not fully understood. Thus, the objective of this work was to investigate biochemistry and technological characteristics of WB chicken fillets and their consumer acceptance. WB fillets were evaluated in regards to color, pH, approximate chemical composition, water holding capacity, cooking loss, shear force, total and soluble collagen, and comparison estimated of pyridinoline. The sensorial analysis used real size images of fillets. The WB showed changes in physical parameters such as an increase in luminosity and shear force. In regards to the chemical parameters, showed an increase in pH value, moisture content, lipids, and mineral, and protein content reduction. There were biochemistry changes in the collagen with an increase of 17.32% in total collage content and a reduction by 30.96% in the estimated pyridinoline content. Technological parameters were negatively altered by a reduction in water holding capacity. WB fillets showed a low acceptance rate and intention to purchase. Results show the WB meat presented biochemistry and technological characteristics compromised besides a low acceptance and purchase intention, leading to economic losses for the poultry sector.

Intramuscular collagen characteristics and expression of related genes in skeletal muscle of cull cows receiving a high-energy diet

We aimed to investigate differences in the synthesis and metabolism of intramuscular collagen in the Longissimus thoracis (LT) muscle between heifers and cull-cows fed high-energy diet. Ten cull-cows, (74.9 ± 3.2 months age, weighing 536 ± 14.55 kg) and ten heifers (18.4 ± 3.2 months age, weighting 310.5 ± 14.5 kg) were fed with high-energy diets for 150 days. The total collagen content did not differ between treatments. Greater collagen solubility was observed in heifers than cull-cows, although no differences in lysyl oxidase activity were observed between treatments. No differences were observed for mRNA expression of CO1A1, MMP2, MMP9 and TIMP2 between treatments. However, cull-cows presented greater mRNA expression of COL3A1, TIMP1 and TIMP3 than heifers. Our data give no indication that feeding a high-energy diet to cull-cows decreases the concentration of intramuscular collagen in the LT muscle or increases its solubility in respect to the collagen solubility in LT muscles from heifers on the same diet.

The effect of encapsulated active principles (eugenol, thymol and vanillin) and clove and rosemary essential oils on the structure, collagen content, chemical composition and fatty acid profile of Nellore heifers muscle

The objective of the present experiment was to evaluate the effects of encapsuled active principles (eugenol, thymol and vanillin blend), and clove and rosemary essential oils inclusion into the finishing diets of Nellore heifers on chemical composition, collagen content, fatty acid profile and structural traits (fibers types, type I and III collagen and sarcomere length) of longissimus muscle. Treatments had no effect (P > .05) on type of fiber, the meat chemical composition or in the muscle fatty acid profile. However, the diet with clove and rosemary essential oil and the active principle blend led to an increase in sarcomere length, higher soluble collagen content and a lower amount of type III collagen (P < .05). The mixture of both active principles and essential oils clove and cinnamon essential oil, have a potential use in animal feed, favoring a greater sarcomere length, that is directly related to the increase of the meat tenderness, without altering the meat chemical composition or fatty acid profile.