Extraction, characterization and molecular structure of bovine skin gelatin extracted with plant enzymes bromelain and zingibain.

Bovine skin was incubated with plant enzymes bromelain (B) and zingibain (Z) at the level of 0, 5, 10, 15, 20 and 25 unit/g of skin and gelatin was extracted at 60 °C for 6 h. Control gelatin was extracted without enzymatic pretreatment. The yield and gel strength were 17.90% and 283.35 g for the control samples and 22.26% and 160.88 g for B20 samples. The zingibain extracted gelatin (GEZ) samples failed to form gel. Viscosities of GEZ gelatins were significantly (P < 0.05) lower than the gelatins extracted using bromelain (GEB). ß and α chains were absolutely degraded in all GEB and GEZ samples. Only smear bands were observed in GEZ gelatins whereas GEB samples revealed presence of low molecular weight polypeptides. Loss of molecular order was noticed in Z5 as elaborated by Fourier transform infrared (FTIR) spectroscopy. Larger particle size, denser and inter-connected irregular network was observed in B20 under scanning electron microscopy. Based on the results obtained, bromelain, particularly at level 20, could be used to obtain a better quality gelatin with higher yield compared to zingibain.

Antioxidant and Antimicrobial Potential of Peptide from Rabbit Meat Hydrolysate Prepared by Trypsin and Zingibain.

<b>Background and Objective:</b> Rabbit meat is a livestock product potentially viable as a protein source to obtain peptides. Antioxidant and antimicrobial peptides are ingredients extracted from various foods through enzymatic hydrolysis, chemical hydrolysis and fermentation to produce health-promoting foods. This research aims to investigate the potential of rabbit meat as a source of antioxidant and antimicrobial peptides through hydrolysis using trypsin and zingibain enzymes. <b>Materials and Methods:</b> This research conducted an explorative-descriptive approach, focusing on antioxidant and antimicrobial activity. Rabbit meat was extracted using trypsin, zingibain and a combination of trypsin and crude extract zingibain. The hydrolyzed rabbit meat extract was tested at intervals of 0, 2, 6, 16, 24, 40 and 48 hrs to determine the degree of hydrolysis and the profile of hydrolyzed proteins with electrophoresis SDS PAGE. The antioxidant activity was tested using the DPPH method and the antimicrobial activity using agar well diffusion method. <b>Results:</b> The degree of hydrolysis increased with the hydrolysis time. The highest protein content of rabbit meat extract hydrolyzed with trypsin was 287.65 mg/mL, observed during 12 hrs hydrolysis. The optimum conditions for the hydrolysis of rabbit meat protein were obtained at 24 hrs, with an IC₅₀ value of 52.45% hydrolyzed by trypsin. As per antimicrobial activities, <i>Escherichia coli</i> and <i>Salmonella</i> sp. were more effective in inhibiting rabbit meat hydrolysates compared to <i>Pseudomonas aeruginosa</i> and <i>Staphylococcus aureus</i>. The inhibition of all pathogen increased until 12 hrs hydrolysis but decreased in 24 hrs hydrolysis. <b>Conclusion:</b> The combination zingibain enzyme and trypsin is feasible for hydrolyzing rabbit meat and the optimum hydrolysis time was 24 hrs with IC₅₀ 52.45 ppm, although accompanied by reduction in antibacterial activities.

The effect of extended refrigerated storage on the physicochemical, structural, and microbial quality of sous vide cooked biceps femoris treated with ginger powder (zingibain).

The aim of the study was to investigate quality and shelf life of beef meat cooked under sous vide conditions then extended refrigerated storage for 10 weeks. Biceps femoris (n = 6) from six to seven year old cows were treated with 2 g/L ginger powder (GP) containing zingibain or control (no injection) and were then cooked in sous vide conditions at 65 °C for 1 h or 8 h. Cooked samples were evaluated for physicochemical (pH, total water content, cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis (TPA), L*, a*, b* properties and thiobarbituric acid reactive substance (TBARS)), microstructure (scanning electron microscopy) and microbiological (Brochothrix thermospacta, Clostridium perfringens, Lactic acid bacteria, Listeria monocytogenes, Salmonella spp, and yeasts and moulds) quality after vacuum packing, cooking, then refrigerated storage at 4 °C for 0, 2, 4, 8 or 10 weeks. Physicochemical parameters were improved by GP treatment (P < 0.05) while there was no effect of storage time on WBSF, TPA or microstructure. The microbial quality of sous vide cooked meat in refrigerated storage appeared to be four weeks and oxidation shelf life of the cooked meat was found to be two weeks under refrigerated storage.

Sensory and Physical Characteristics of M. biceps femoris from Older Cows Using Ginger Powder (Zingibain) and Sous Vide Cooking.

This study aimed to evaluate the sensory and physical characteristics of zingibain-injected meat combined with sous vide cooking. M. biceps femoris (BF; n = 12) acquired from 6-7 year old Angus cows were cooked using the sous vide method at 65 °C, for 8 h or 12 h, either with ginger powder (GP) injected in a 2 g/L solution in water (treatment) or un-injected (control). The sensory attributes included flavour, juiciness, tenderness, and physicochemical characteristics were Warner-Bratzler shear (WBSF), hardness, total water content (TWC), cooking loss (CL) and collagen content. A significant improvement in tenderness with injection treatment and cooking time was observed, as evaluated through trained sensory panellists, and reduced WBSF and hardness (p < 0.05 for all). The flavour of the meat was not affected by injection treatment or cooking time (p > 0.05), but juiciness and TWC were reduced with longer cooking times (p < 0.01 for both). Soluble collagen increased with injection treatment and cooking time (both p < 0.05). Moderate to high correlations were found between sensory and physical measurements for tenderness and juiciness. The longer cooking time (12 h) with GP injection treatment caused over tenderization of the meat. The soft texture associated with over-tenderization may be suitable for some specialised consumer markets, for instance, the elderly population with chewing difficulties. Improving the eating quality of low-quality meat from old animals through sous vide cooking and the use of ginger proteases may increase the acceptability of lower value beef, potentially enhancing the commercial value of carcasses typically produced in the beef industry.

Data in support of three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes.

This paper describes data related to a research article titled "Three Phase Partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes" (Gagaoua et al., 2015) [1]. Zingibain (EC 3.4.22.67), is a coagulant cysteine protease and a meat tenderizer agent that have been reported to produce satisfactory final products in dairy and meat technology, respectively. Zingibains were exclusively purified using chromatographic techniques with very low yield purification. This paper includes data of the effect of temperature, usual salts and organic solvents on the efficiency of the three phase partitioning (TPP) system. Also it includes data of the kinetic activity characterization of the purified zingibain using TPP purification approach.

Three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes.

The present work describes for the first time an elegant non-chromatographic method, the three phase partitioning for the purification and recovery of zingibain, a milk-clotting enzyme, from Zingiber officinale rhizomes. Factors affecting partitioning efficiency such as (NH4)2SO4 saturation, crude extract to t-butanol ratio and pH on zingibain partitioning were investigated. Optimal purification parameters were 50% (NH4)2SO4 saturation with 1.0:1.0 ratio of crude extract:t-butanol at pH 7.0, which gave 14.91 purification fold with 215% recovery of zingibain. The enzyme was found to be exclusively partitioned in the aqueous phase. The enzyme showed a prominent single band on SDS-PAGE. It is a monomeric protein of 33.8 kDa and its isoelectric point is 4.38. The enzyme exhibited maximal proteolytic activity at a temperature of 60 °C and pH 7.0. It was found to be stable at 40-65 °C during 2 h. The enzyme was found to be highly stable against numerous metal ions and its activity was enhanced by Ca(2+), K(+) and Na(+). It was completely inhibited by heavy metal ions such as Cu(2+) and Hg(2+) and partially by Cd(+). Zingibain milk-clotting activity (MCA) was found to be highly stable when stored under freezing (-20 °C) for 30 days compared at 4 °C.