Dynamic Changes of Physicochemical Properties of Pineapple Juice During Fermentation with Allochthonous and Autochthonous Yeasts under Different Conditions

Abstract

The allochthonous yeasts are generally exploited as starter for fruit wines production. The unique abilities of these yeasts are useful to fermented beverages industry. The autochthonous yeasts, non-Saccharomyces yeasts have been reported to be wild yeasts that produce the unique flavors and exceptional quality when used for traditional wine fermentation. Pineapple juice is one of the juice contains sufficient nutrients for yeast to grow and ferment quality fruit wine. However, the juice contains proteolytic enzymes that may have an inhibitory effect on yeast during fermentation. Thus, species specific strains of yeast may be a key for pineapple juice fermentation. The objective of this research was to investigate the changes of physicochemical properties of fresh crushed Pattawia variety pineapple juice during fermentation with allochthonous and autochthonous yeasts under different conditions including; (i) shaking at 110 rpm in an orbital shaker, (ii) shaking at 110 rpm for 3 days then standing still, and (iii) without shaking. It was found that yeasts population of all conditions rapidly increased approximately 2 log cycles in day 1. After fermentation, allochthonous yeast could reduce total soluble solid of fresh crushed pineapple juice to 4.0–5.0 o brix through fermentation days while autochthonous yeast had relatively lower nutrients consumption rate as compared with the former. This study also demonstrated that different cultivation condition affected growth profiles and nutrients consumption behavior of yeasts resulting to changes of physicochemical properties of the juice. Based on fermentation profiles investigated, autochthonous pineapple yeast, M. guilliermondii, was potential for applications in making beverage derived from pineapple juice fermentation.

Keywords

• allochthonous yeast
• autochthonous yeast
• fermentation
• fruit juice
• pineapple