Effects of freeze-drying and spray-drying on donkey milk volatile compounds and whey proteins stability. (February 2018)

• Record Type: Journal Article
• Authors: Vincenzetti, Silvia; Cecchi, Teresa; Perinelli, Diego Romano; Pucciarelli, Stefania; Polzonetti, Valeria; Bonacucina, Giulia; Ariani, Ambra; Parrocchia, Liliana; Spera, Daniela Maria; Ferretti, Ersilia; Vallesi, Paola; Polidori, Paolo
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 88(2018)
• Page Start: 189
• Page End: 195
• Publication Date: 2018-02
• Subjects: Donkey milk -- Spray-drying -- Freeze-drying -- Whey proteins -- Volatile compounds; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2017.10.019
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: In this work, the profile of the volatile compounds has been determined for the first time in fresh donkey milk and in donkey milk subjected to accelerated shelf-life test, freeze-drying and spray-drying processes. The effects of freeze-drying and spray-drying processes in donkey milk have been analyzed also on three representative whey proteins, β-lactoglobulin, α-lactalbumin and lysozyme, by determining the total amount, the enzymatic activity and the thermal stability. Considering the volatile compounds in fresh donkey milk, 2-heptanone, 1, 3-bis (1, 1-dimethylethyl)-benzene, nonanal, d -limonene, octanoic acid, and 1-octanol were detected. The accelerated shelf-life test revealed a constant increase of octanoic acid, 2-heptanone, and nonanal compared to fresh donkey milk (P < 0.001) and the appearance of ethyl octanoate, ethyl dodecanoate, 2-nonanone and 2-undecanone, indicating that these compounds may be highly eligible markers of donkey milk shelf-life. Freeze-drying and spray-drying affected β-lactoglobulin and lysozyme content in donkey milk. In particular, spray-drying process decreased significantly lysozyme enzymatic activity (58% of residual activity) and β-lactoglobulin content (6.43 mg/mL in fresh milk vs 5.51 mg/mL in spry-dried milk) due to the high temperature to which donkey milk is subjected. Highlights: Volatile compounds on donkey milk has been determined for the first time. Potential markers of donkey milk shelf life have been determined. Freeze-drying process does not alter donkey's milk whey protein content. Spray-drying process affects lysozyme activity and β-lactoglobulin content.