Effects of the decontamination of a fresh tiger nuts' milk beverage (horchata) with short wave ultraviolet treatments (UV-C) on quality attributes

• Published in: Innovative food science & emerging technologies Vol. 13; pp. 163 - 168
• Main Authors: Corrales, Margarita, de Souza, Poliana M., Stahl, Mario R., Fernández, Avelina
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2012
• Subjects: Bacteria; Beverages; Color; Commercialization; Food; Germicide; Microorganisms; Milk; Minimal processing; Non-thermal processing; Nuts; Short wave; Tiger nuts; Ultraviolet treatment; UV-C; Vegetable milk; UV-C; Ultraviolet treatment; Germicide; Vegetable milk; Minimal processing; Tiger nuts; Non-thermal processing; Food
• ISSN: 1466-8564; 1878-5522
• DOI: 10.1016/j.ifset.2011.07.015

In this work, the feasibility of short wave ultraviolet radiation (UV-C) to achieve the physicochemical and microbiological stability of a tiger nuts' milk beverage was evaluated. Colour changes measured as total color difference and browning index were imperceptible even when the liquid was treated at high UV-C doses. Likewise, the fat content and its oxidation level remained unaffected. By contrast, the antioxidant capacity of treated samples decreased with increasing doses of UV-C. And in particular, the peroxidase activity decreased up to 85% at the highest UV-C dose applied. Notably, UV-C effectively inactivated up to 3-log10 cycles of spoilage-related microorganisms (yeasts and moulds, mesophilic flora and psychrotrophic bacteria). Horchata's freshness determined according to pH values, was extended 2 to 4days if samples were UV treated. In summary, UV-C showed its suitability to commercialization possibilities with a minimum impact on its physicochemical quality attributes. Industrial relevance: Jellification of starch hinders the use of thermal treatments to pasteurize fresh tiger nuts’ milks; consequently those products are highly perishable and have to face severe commercialization restrictions. We proved that UV-C is a suitable minimal processing technology for this type of products, inactivating efficiently the main contaminant microorganisms, and thus increasing significantly the shelf-life. ► Control of microbial contamination of a tiger nuts milk beverage by UVC. ► Quality parameters preserved. ► Antioxidant capacity slightly affected. ► New markets opening by non-thermal treatments.