TY - JOUR
T1 - Understanding the effect of storage temperature on the quality of semi-skimmed UHT hydrolyzed-lactose milk
T2 - an insight on release of free amino acids, formation of volatiles organic compounds and browning
AU - Bottiroli, Riccardo
AU - Troise, Antonio Dario
AU - Aprea, Eugenio
AU - Fogliano, Vincenzo
AU - Gasperi, Flavia
AU - Vitaglione, Paola
PY - 2021/3
Y1 - 2021/3
N2 - Proteolytic side activity of the lactase preparations (LPs) intended for ultra-high temperature hydrolyzed-lactose milk (UHLM) production induces changes in the product quality during shelf-life. The problem is particularly relevant when the enzyme is added aseptically in the packaging (“in pack” process), while the negative quality effects can be mitigated following the “in batch” process adding the LP before thermal sterilization. In this study, we monitored the quality over time of UHLM produced “in batch” and stored at 4, 20, 30 and 40 °C focusing on proteolysis, volatiles organic compounds (VOCs) formation and color changes. The goal was to identify the key reactions and compounds relevant for the product quality. An increase in storage temperature determined significant changes in the free amino acids profile increasing Strecker aldehydes and methyl ketones formation. At 30 and 40 °C, Maillard reaction and lipid oxidation ended up in a modification of the milk color, whereas at 4 and 20 °C no significant alteration was observed. Altogether, the results suggested a coordinate involvement of Maillard reaction, protein and lipid oxidation to milk browning and off-flavors formation in UHLM.
AB - Proteolytic side activity of the lactase preparations (LPs) intended for ultra-high temperature hydrolyzed-lactose milk (UHLM) production induces changes in the product quality during shelf-life. The problem is particularly relevant when the enzyme is added aseptically in the packaging (“in pack” process), while the negative quality effects can be mitigated following the “in batch” process adding the LP before thermal sterilization. In this study, we monitored the quality over time of UHLM produced “in batch” and stored at 4, 20, 30 and 40 °C focusing on proteolysis, volatiles organic compounds (VOCs) formation and color changes. The goal was to identify the key reactions and compounds relevant for the product quality. An increase in storage temperature determined significant changes in the free amino acids profile increasing Strecker aldehydes and methyl ketones formation. At 30 and 40 °C, Maillard reaction and lipid oxidation ended up in a modification of the milk color, whereas at 4 and 20 °C no significant alteration was observed. Altogether, the results suggested a coordinate involvement of Maillard reaction, protein and lipid oxidation to milk browning and off-flavors formation in UHLM.
KW - Hydrolyzed-lactose milk
KW - Maillard reaction
KW - Shelf-life
KW - Storage temperature
U2 - 10.1016/j.foodres.2021.110120
DO - 10.1016/j.foodres.2021.110120
M3 - Article
AN - SCOPUS:85099500538
SN - 0963-9969
VL - 141
JO - Food Research International
JF - Food Research International
M1 - 110120
ER -