Fermentation of orange-passion fruit juice using fruit-origin strains of Lactobacillus rhamnosus and Fructobacillus tropaeoli

RUIZ RODRÍGUEZ LG, MOHAMED F; GOLDNER MC; DE VUYST L; RUIZ RODRÍGUEZ LG, MOHAMED F, MEDINA R, HÉBERT EM, MOZZI F.

CORDOBA

Congreso; VII CONGRESO INTERNACIONAL DE CIENCIA Y TECNOLOGÍA DE ALIMENTOS (CICYTAC 2018); 2018

Ministerio de Ciencia y Tecnología de Córdoba

Fruits and vegetables have a short shelf-lifeand are usually consumed fresh or minimally processed. The prevailingpreservation technologies may cause undesirable physical and nutritionalchanges in the food matrices. Lactic acid fermentation of fruits and vegetableshas become an attractive alternative for their conservation. Further, fermentedfruits can be an excellent choice to satisfy the increasing demand for non-dairyfunctional drinks. The rational selection of strains with interesting metabolicprofiles is crucial to preserve and/or improve the sensory quality, safety, andhealth-beneficial characteristics of the raw material through fermentations.Therefore, the behavior, survival, and sensorial effects of a starter culturecomposed of the fruit-origin strains Lactobacillus rhamnosus H3F-210 andFructobacillus tropaeoli FYP-H3-450 (1:1) for the fermentation of anatural orange-passion fruit (50:50) juice was evaluated. The strains, selectedfor their ability to synthesize ethyl esters (Lb. rhamnosus) andmannitol (F. tropaeoli), acidifying capacity, and capability to surviveunder the juice conditions, were cultured (2%, v/v) at 30°C for 24 h in thejuice (initial pH= 3.2). The starter culture survived the culture conditions,although no significant increase in bacterial counts or pH change were noticed.Also, a low decrease in the glucose and fructose contents ( 25% each) with aconcomitant but limited mannitol, lactic acid and acetic acid production wasfound. The fermented (FJ) and non-fermented (control, CJ) juices were evaluatedfor their nutrient and sensory profiles. Although the nutrient composition ofboth juices was similar, the protein, phenolic compound, and flavonoid contentswere lower in the FJ than in the CJ. No differences in the volatile compoundprofile (SPME-GC-MS) were noticed, detecting 8 main flavor compoundscorresponding to the raw fruit juice. The sensory analysis (paired comparisontest) showed that fermentation significantly modified only the taste attribute;the FJ was perceived with a dairy taste, while the CJ as fresh one. Regardingthe consumer acceptability test (112 panelists, 9-point hedonic scale), thegrades of global acceptance of both FJ (5.91) and CJ (6.21) were notsignificantly different, showing that fermentation did not affect the sensoryproperties of the matrix. During the shelf-life (60 days, 4°C) the microbialcounts slightly decreased (< 1 log CFU/mL), the pH remained constant, and nodeteriorating microorganisms were detected along the storage period. Inconclusion, fermentation with the selected cultures preserved the nutritional,sensorial, and global acceptability features of the orange-passion fruit juice.Additionally, this matrix could be used as vehicle for lactic acid bacteriawith specific properties. Thus, lactic fermentation may provide added value tofruit, contributing to the development of novel functional fermented fruitproducts for the market.