Enhanced gelling performance of oxhide gelatin prepared from cowhide scrap by high pressure-assisted extraction

Abstract

In this study, the feasibility of preparing oxhide gelatin from cowhide scrap by high pressure assisted-liquid extraction was verified. Different processing conditions, including high pressure time (15 to 25 min), pressure (250 to 350 MPa), and liquid-to-solid ratio (1:3 to 1:5), were optimized through response surface methodology. Under the optimum manufacturing conditions, when the high-pressure processing (HPP) time was 22 min, the pressure was 289 MPa, and the liquid-to-solid ratio was 1:4, the highest extraction yield (36%) and gel strength (224 g) were achieved. Based on DSC, XRD, FTIR, SEM, gelling and melting temperatures, HPP led to the structural modification of the gelatinized collagen, which enhanced the rearrangement of the gel structure during the gelation process and made it have better gelling properties. In addition, compared with the commercial sample, they do not differ significantly in the relaxation time and peak area of prepared oxhide gelatin. These findings provide new insights into the practicability of HPP during the preparation of oxhide gelatin, which can noticeably reduce the processing time and be applied to industrial production. PRACTICAL APPLICATION: Compared with traditional processing, a high pressure-assisted extraction process can noticeably reduce the processing time while producing cowhide gelation with similar physicochemical and functional properties. Meanwhile, high pressure processing (HPP) led to the structural destruction of the cowhide and gelatinized collagen, which enhanced the rearrangement of the gelatin structure during the gelation process and made it have better gelling properties. Importantly, high pressure-assisted extraction can facilitate the use of a low-cost raw material and improve the preparation efficiency of oxhide gelatin, which shows great potential in large-scale and efficient industrial production and the quality control of oxhide gelatin.

Keywords: byproduct utilization; cowhide scrap; gelling performance; high pressure processing; low field NMR; oxhide gelatin.