Jerusalem Artichoke Tuber Processing: Influence of Pre-Treatment Methods, Lactic Acid, and Propionic Acid Bacteria Strains on Functional Fermented Beverage Production.

Abstract

Fermented plant-based products are rapidly gaining popularity. Jerusalem artichoke is a medicinal plant that can be used to make fermented beverages. Samples were subjected to pretreatment (ultrasound at 35 kHz for 2, 4, and 6 min, freezing at -80 °C and -17 °C) while an untreated sample was used as control. It was shown that all types of pretreatments did not lead to an increase in protein, solids, polyphenols, and carbohydrates compared to the control sample. The greatest decrease in the values of these indicators occurs when pre-freezing tubers are used for Jerusalem artichoke dispersion production. It was also found that samples frozen at -80 °C had a significantly higher concentration of Ca, Si, Mg, and P whereas untreated samples frozen at -17 °C had more Al, K, Cu, Sr, and Cr. The processing method can affect the sensory descriptors of Jerusalem artichoke tuber dispersions to different extents, but the preference was for the control sample without pre-treatment. The fermentation of Jerusalem artichoke tuber dispersions demonstrated that S. thermophilus induced the most rapid fermentation (pH 4.75 in 5 h). The highest antioxidant activity after fermentation (55.39% FRSA) was shown for L. acidophilus H9, while the highest % FRSA value during the storage period was for L. bulgaricus (67.5%) on day 5 after fermentation. The highest viability among all selected microorganisms was detected for L. bulgaricus, L. acidophilus AT-41, and B. coagulans MTCC 5856 with the increase in biomass content by 2.3, 2.27, and 2.12 log₁₀CFU/ml after fermentation. According to the results of sensory evaluation using hybrid hedonic scale the best results were shown for samples fermented with L. bulgaricus.