Characteristics and properties of goat meat gels as affected by setting temperatures.

Effects of different setting temperatures (40-70 °C) on properties of goat meat gels after heating at 90 °C were investigated. Setting at 60 °C with subsequent heating at 90 °C yielded the gel with the highest breaking force along with coincidentally lowest expressible moisture content (p < 0.05). The highest TCA-soluble peptide content was found in gel set at 70 °C (p < 0.05). Slight decrease in myosin heavy chain band intensity was noticeable when setting temperature increased. As setting temperatures increased, a∗ and b∗-values of gels generally increased, while L∗-values decreased (p < 0.05). Gel set at 60 °C had highest hardness, gumminess and chewiness (p < 0.05). Gel set at 60 °C had the most compact network with immense connectivity of protein strands. Gels set at 40-60 °C had higher texture and overall likeness scores, compared to the control (p < 0.05). Prior setting at 60 °C was recommended for making the good quality goat meat gel.

Characteristics and gelling properties of gelatin from goat skin as affected by drying methods.

Characteristics and gel properties of spray-dried goat skin gelatin (SDGG) and freeze-dried counterpart (FDGG) were determined, in comparison with commercial bovine gelatin (BG). SDGG gel had the similar gel strength to FDGG gel and their gel strengths were higher than that of BG gel. SDGG gel showed slightly higher a* and b* values as well as the higher solution turbidity than those of FDGG. Both SDGG and FDGG solutions could set at room temperature (25-28 °C) within 18.52-19.30 min and showed the gelling and melting temperatures of 25.14-25.23 and 34.09-34.18 °C, respectively. Gels from SDGG and FDGG had the denser structure with smaller voids than that from BG. Therefore, drying methods affected the characteristics and gel properties of gelatin from goat skin to some degree.

Characteristics and Gel Properties of Gelatin from Goat Skin as Influenced by Alkaline-pretreatment Conditions.

Characteristics and properties of gelatin from goat skin pretreated with NaOH solutions (0.50 and 0.75 M) for various times (1 to 4 days) were investigated. All gelatins contained α-chains as the predominant component, followed by ß-chain. Gelling and melting temperatures of those gelatins were 23.02°C to 24.16°C and 33.07°C to 34.51°C, respectively. Gel strength of gelatins increased as NaOH concentration and pretreatment time increased (p<0.05). Pretreatment for a longer time yielded gelatin with a decrease in L*-value but an increase in b*-value. Pretreatment of goat skin using 0.75 M NaOH for 2 days rendered the highest yield (15.95%, wet weight basis) as well as high gel strength (222.42 g), which was higher than bovine gelatin (199.15 g). Gelatin obtained had the imino acid content of 226 residues/1,000 residues and the gelatin gel had a fine and ordered structure. Therefore, goat skin gelatin could be used as a potential replacer of commercial gelatin.

Characteristics and gel properties of gelatin from goat skin as affected by pretreatments using sodium sulfate and hydrogen peroxide.

BACKGROUND: Goat skin can be used as an alternative raw material for gelatin production, in which pretreatment conditions can determine the characteristics or properties of the resulting gelatin. The present study aimed to investigate the effect of pretreatment using sodium sulfate (Na2SO4) and hydrogen peroxide (H2O2) on properties of goat skin gelatin. RESULTS: Pretreatment of skin using Na2SO4 (0-1 mol L(-1)) increased the yield of gelatin in a concentration-dependent manner. When skins with prior Na2SO4 treatment were bleached using H2O2 (0-2 mol L(-1)), the resulting gelatin showed higher yield and gel strength than those without prior Na2SO4 treatment. All gelatins had α-chain as a major component, followed by ß-chain. The degradation induced by H2O2 was lower in gelatin with prior Na2SO4 treatment. L* values increased with increasing H2O2 concentrations (P < 0.05) due to the bleaching effect of H2O2. With Na2SO4 and H2O2 pretreatments, gelatin gel had a finer and more ordered microstructure. Gelatin had an imino acid content of 217 residues/1000 residues with gelling and melting temperature of 22.49 and 32.28 °C, respectively. CONCLUSION: The optimal pretreatment conditions for gelatin extraction from goat skin included soaking the skin in 0.75 mol L(-1) NaOH, followed by treatment using 0.75 mol L(-1) Na2SO4 and subsequent bleaching with 2 mol L(-1) H2O2. This resulted in gelatin with superior quality to the untreated counterpart.