Freezing-then-aging treatment improved the protein digestibility of beef in an in vitro infant digestion model.

Affiliation

Lee S(1), Jo K(1), Jeong HG(1), Yong HI(2), Choi YS(2), Kim D(3), Jung S(4).
Author information:
(1)Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, South Korea.
(2)Research Group of Food Processing, Korea Food Research Institute, Wanju 55365, South Korea.
(3)Korea Institute for Animal Products Quality Evaluation, Sejong-si 30100, South Korea.
(4)Division of Animal and Dairy Science, Chungnam National University, Daejeon 34134, South Korea. Electronic address: [Email]

Abstract

In vitro protein digestibility of freezing-then-aged beef was investigated in an infant digestion model. The treatments were divided into freezing-then-aging (FA) and aging-only (AO) groups. Carbonyl and total free sulfhydryl contents were the same between both groups for 14-day aging. Freezing had no effect on beef myofibrillar protein tertiary structure. Although caspase-3 activity did not differ, the FA group showed higher cathepsin B activity than the AO group (p < 0.05). The 10% trichloroacetic acid-soluble α-amino content was higher in FA than AO group, on aging day 14 (p < 0.05). Post in vitro digestion of beef aged for 14 days, the FA group had a higher content, than the AO group, of α-amino groups and proteins digested under 3 kDa (p < 0.05). An electrophoretogram of the digesta showed improved digestion of actin in the FA group. Collectively, the freezing-then-aging process enhanced the protein digestibility of beef in this in vitro infant digestion model.