The Effect of Fermentation with Kefir Grains on the Physicochemical and Antioxidant Properties of Beverages from Blue Lupin (Lupinus angustifolius L.) Seeds.

Łukasz Łopusiewicz,Emilia Drozłowska,Annett Gefrom,Paulina Trocer,Monika Sienkiewicz,Paweł Kwiatkowski,Artur Bartkowiak

doi:10.3390/molecules25245791

Abstract

Plant derived fermented beverages have recently gained consumers’ interest, particularly due to their intrinsic functional properties and presence of beneficial microorganisms. Three variants containing 5%, 10%, and 15% (w/w) of sweet blue lupin (Lupinus angustifolius L. cv. “Boregine”) seeds were inoculated with kefir grains and incubated at 25 °C for 24 h. After processing, beverages were stored in refrigerated conditions (6 °C) for 21 days. Changes in microbial population, pH, bioactive compounds (polyphenolics, flavonoids, ascorbic acid), reducing sugars, and free amino acids were estimated. Additionally, viscosity, firmness, color, and free radicals scavenging properties were determined. Results showed that lactic acid bacteria as well as yeast were capable of growing well in the lupin matrix without any supplementation. During the process of refrigeration, the viability of the microorganisms was over the recommended minimum level for kefir products. Hydrolysis of polysaccharides as well as increase of free amino acids was observed. As a result of fermentation, the beverages showed excellent DPPH, ABTS+·, ·OH, and O2− radicals scavenging activities with a potential when considering diseases associated with oxidative stress. This beverages could be used as a new, non-dairy vehicle for beneficial microflora consumption, especially by vegans and lactose-intolerant consumers.

Highlights

Increasing consumers’ demand for healthy foods and awareness of the impact of dietary habits in human well-being has prompted the efforts of developing novel foods with defined health benefits [1,2,3,4,5].Nowadays, a great number of novel functional foods are available on the market with dairy foods and beverages representing an important segment [1]
The bacterial and yeast counts were maintained in the samples over the recommended for kefir level >107 CFU/g and >104 CFU/g, for bacteria and yeast, respectively
During storage, some significant fluctuations (p < 0.05) of both Lactic Acid Bacteria (LAB) and yeast counts were observed, which may be linked with different nutrients availability in the samples

Summary

Introduction

Increasing consumers’ demand for healthy foods and awareness of the impact of dietary habits in human well-being has prompted the efforts of developing novel foods with defined health benefits [1,2,3,4,5]. A great number of novel functional foods are available on the market with dairy foods and beverages representing an important segment [1]. Milk consumption has been declining, and consumer demand for cow’s milk alternatives increased as a result of the increase in the diagnosis of lactose intolerance, allergies, and cholesterol issues [10,11,12,13]. The ongoing trend of vegetarianism, with an increasing number of vegan/vegetarian consumers, has established a massive worldwide importance of non-dairy plant-based dairy substitutes [10,14,15,16]. Not wishing to consume food of animal origin, vegan consumers are looking for substitutes that could enrich their diet and contribute to a good health

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Results

Conclusion