Heat treatment and gamma radiation effects on the physical-chemical, microbiological and sensory stability of pure sugarcane juice or added with fruit juices, stored under refrigeration

Author(s)

Aline Cristine Garcia de Oliveira

• Document type: Master's Dissertation
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2007-03-09

Examining board members

Marta Helena Fillet Spoto; Solange Guidolin Canniatti Brazaca; Cristina Paiva de Sousa

• Advisor: Marta Helena Fillet Spoto

Abstract

Sugarcane juice is a taste drink, energetic, no alcoholic that conserves all the nutrients in cane sugar. It was very appreciated by the Brazilian population and its production has been shown to be a highly lucrative business. This research had the following objectives: evaluate the acceptance of the consuming market and the stability of pure sugarcane juice or added with natural fruit juices, submitted of heat treatment (70&#176;C/ 25 min) and/ or gamma radiation (2,5 kGy) and stored in high density polyethylene bottles, under refrigeration (5 &#177; 1&#176;C). Sugarcane juice market test was evaluated through the application of 350 questionnaires on six São Paulo cities. Sugarcane juice stability was evaluated through microbiological (psicrothrophic count, lactic bacteria and yeasts and molds count), physical-chemical (pH, color, titratable acidity, soluble solids, ratio and polyphenoloxidase activity) and sensory (hedonic test) parameters. Centesimal composition was determined analyzing: humidity, caloric value, total carbohydrates, total and reducing sugars, lipids, proteins, ascorbic acid, ash and minerals. Sugarcane juice shelf life period was determinate ever 7 days over a period of 42 days stored under refrigeration. The data were submitted to the variance analysis and compared by Tukey&#39;s test (p<0,05). Among the 350 interviewed people, more of the half one is interested about its habitual food safe and care about street foods. Sandwiches had been cited foods as routinely consumed, followed for the sugarcane juice and &#34;pastel&#34;. Among the interviewed ones, 80% had mentioned to appreciate sugarcane juice. It had not correlation between age and school age and the preference for the consumption form was with lemon juice addition. About 55% of the interviewed ones had mentioned that would more frequently consume sugarcane juice processed and packed. Sugarcane juice processament didn&#39;t modify the flavor and taste of the drink. It was concluded from the sensory analyses that the best mixture was that formulated with sugarcane juice and 4% of lemon juice as well as 10% of pineapple juice. Sugarcane juice centesimal composition wasn&#39;t altered by fruit juice concentration addition. However, sugarcane juice added with 10% pineapple juice incremented manganese and reducing sugars when compared with pure sugarcane juice and added with 4% lemon juice. The market test prefered mixture was shown to be that containing sugarcane juice and natural lemon juice for evaluation the shelf life. Sugarcane juice added with 4% of lemon juice submitted to gamma radiation, heat treatment combinated with gamma radiation and heat treatment remaining satisfactory microbiological, sensory and physicalchemical characteristics until 28, 35 and 42 days respectively, after processing. These results indicated that the heat treatment was effective for sugarcane juice preservation. (AU)

• FAPESP's process: 05/53042-6 - Effects of the thermal processing and gamma radiation on the physico-chemical, microbiological and sensorial stability of pure sugarcane juice and with added fruit juices stored under refrigeration
• Grantee: Aline Cristine Garcia de Oliveira
• Support Opportunities: Scholarships in Brazil - Master