Insight into the role of lactic acid bacteria in the development of a novel fermented pistachio (Pistacia vera L.) beverage

Abstract

This study aimed to assess the fermentability of a pistachio-based beverage. The effects of lactic acid fermentation on the odor profile and the stability of the beverage were also assessed. To this end, a procedure for obtaining a pistachio beverage was developed, and the nutritional composition of the beverage was obtained. The beverage was characterized by a high content of fiber (2.9%), fat (4.6%), and protein (2%), and contained high amounts of K and Mg. For the experiment, 43 cultures of the following lactic acid bacteria were used: Companilactibacillus paralimentarius, Companilactibacillus kimchi, Levilactibacillus brevis, Lactiplantibacillu pentosus, Lactiplantibacillus plantarum, Lactiplantibacillus paraplantarum, Latilactobacillus curvatus, Leuconostoc pseudomesenteroides, and Furfurilactobacillus rossiae. The cultures were evaluated for the following technological characteristics: i) growth and acidifying activity, ii) production of exopolysaccharides; iii) presence of histidine decarboxylase (hdcA) gene; iv) antimicrobial activity against Listeria innocua. The cultures were used in model pistachio-based fermentations to assess their ability to grow and acidify. The odor profile of the beverage after 24 h fermentation was assessed using an electronic nose system (E-nose). The pistachio-based beverage resulted an optimal substrate for lactic acid bacteria that reached loads between 8 and 10 log CFU/mL and acidified the beverage to pH values between 4 and 5.5. In the beverage, viable counts of all cultures remained above 8 log CFU/mL after 30 days of storage at 4 °C. The E-nose analysis represented a valid screening method to evaluate the effects of the fermentative activity of microbial starters on the qualitative characteristics of this novel food matrix.