title: Effects of microbial lipases on hydrolyzed milk fat at different time intervals in flavour development and oxidative stability.
abstract: The interest in application of biocatalysis during natural milk fat flavours development has increased rapidly and lipases have become the most studied group in the development of bovine milk fat flavours. Lipozyme-435, Novozyme-435 and Thermomyces lanuginosus Immobilized (TL-IM) lipases were used to hydrolyze anhydrous milk fat (AMF) and anhydrous buffalo milk fat (ABF) and their volatile flavouring compounds were identified by solid-phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) and then compared at three hydrolysis intervals. Both AMF and ABF after lipolysis produced high amount of butanoic and hexanoic acids and other flavouring compounds; however, highest amount were produced by Lipozyme-435 and Novozyme-435 followed by TL-IM. The hydrolyzed products were assessed by Rancimat-743 for oxidative stability and found both that, for AMF and ABF treated butter oil, Lipozyme-435 and TL-IM were generally more stable compared to Novozyme-435. For both AMF and ABF treated butter oil, Lipozyme-435 was observed to cause no further oxidation consequences which indicates Lipozyme-435 was stable during hydrolysis at 55 °C for 24 h.
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China ; Department of Food Safety and Quality, Zanzibar Food and Drugs Board, P. O. Box 3595, Zanzibar, Tanzania.
authors.forename: Khamis Ali
authors.initials: KA
authors.lastname: Omar
authors.affiliation: Département des Sciences et Techniques de Productions Végétales, Faculté d'Agronomie et des Sciences de l'Environnement, Université Dan Dicko Dan Koulodo de Maradi, BP 465, Maradi, Niger.
authors.forename: Mahamadou Elhadji
authors.initials: ME
authors.lastname: Gounga
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China.
authors.forename: Ruijie
authors.initials: R
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China.
authors.forename: Erasto
authors.initials: E
authors.lastname: Mlyuka
authors.affiliation: State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 Jiangsu China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Wang
keywords: Lipase; Milk fat; Oxidative stability; SPME; Volatile flavouring compounds