Production of freeze-dried beef powder for complementary food: Effect of temperature control in retaining protein digestibility

• Published in: Food chemistry Vol. 433; p. 137419
• Main Authors: Lee, Seonmin, Jo, Kyung, Jeong, Seul-Ki-Chan, Choi, Yun-Sang, Jung, Samooel
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2024
• Subjects: Beef; Freeze-drying; In vitro digestion; Infants; Protein digestibility; Protein structure; CD; GI; TCA; Protein digestibility; BPB; Infants; TBARS; Beef; In vitro digestion; Protein structure; Freeze-drying; EGTA
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2023.137419

•The effect of temperature control during freeze-drying of beef was investigated.•Freeze-dried beef without temperature control showed increased protein oxidation.•Freeze-drying altered the tertiary and secondary structures of beef protein.•In vitro protein digestibility was retained in beef freeze-dried at 2 °C.•Freeze-drying at 2 °C can be used to produce beef powder as a complementary food. This study investigated the effect of temperature control during freeze-drying of beef on the in vitro protein digestibility. Frozen (at − 50 °C for 2 days)-then-aged (at 4 °C for 26 days) beef was freeze-dried at 25 °C (FD1) and 2 °C (FD2) to obtain freeze-dried beef powder. Tryptophan fluorescence intensity and total free sulfhydryl groups of beef myofibrillar proteins decreased (P < 0.05) and increased (P < 0.05) after freeze-drying, respectively. In the myosin fraction of FD2, α-helix increased and β-sheet decreased (P < 0.05) compared to raw beef. In contrast, the actin fraction of FD1 showed a decrease in α-helix and increase in β-sheet (P < 0.05) compared to raw beef. The contents of α-amino group and proteins digested to<3 kDa in the in vitro digesta of beef were retained in FD2 while the α-amino group of FD1 decreased (P < 0.05). Therefore, freeze-drying at 2 °C can efficiently retain in vitro protein digestibility of beef.