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

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.

Production and Characterization of Yogurt-Like Fermented Beverage Based on Camelina (Camelina sativa L.) Seed Press Cake

“…The highest activity against ABTS radical (59.03 ± 4.27%) was noticed for sample CPC-20% on day 7, whereas the highest DPPH inhibition (62.59 ± 5.33%) was found for sample CPC-15% on day 14. This observation is consistent with studies showing that fermented plant-based foods contained significantly more antioxidants than non-fermented raw materials [6,8,19,20]. Interestingly, only slight changes in DPPH radical scavenging activity after fermentation were observed for both variants (p < 0.05).…”

“…However, in the present study a decreased trend of RSC was generally observed in the days following cold storage (p < 0.05). This behavior is associated with the enzymatic hydrolysis of more complex carbohydrates necessary to maintain microbial metabolic activity, as has been reported in previous studies [6,19,20]. In fact, a decrease in soluble carbohydrates was reported by Olukomaiya et al for camelina meal solid-state fermented by food grade Aspergillus strains [8].…”

“…Olukomaiya et al also reported an increase in TPC in solid-state fermented camelina meal [8]. The influence of fermentation on the polyphenolic content in fermented plants has been reported in numerous studies [6,19,20]. This phenomenon was often reported as a generic effect of LAB-induced acidification that increases polyphenols' solubilization and extractability but is mainly strain dependent from specific LAB enzymatic activities that favor the release of polyphenols from glycosylated and more complex forms, with carbohydrates showing lower activity [7,46].…”

“…Fermentation, an ancient food biotechnology is still widely employed in the food industry to extend shelf life as well as to improve the nutritional and sensory attributes of foods [18]. A large number of studies have demonstrated that fermented edible seeds and their byproducts exhibit manifold bioactivities (such as antioxidant, antihypertensive and anticancer effects) [4][5][6][18][19][20] as well as being used in the preparation of innovative food products [2,21,22]. For instance, Olukomaiya et al described the positive effect of semi-solid fermentation in improving the nutritional value and bioactivity of various oilseed press cakes including camelina pressed seeds [8].…”

Antioxidant and Anti-Inflammatory Properties of Bioavailable Protein Hydrolysates from Lupin-Derived Agri-Waste

“…Growing concerns about food issues, as well as strict national and European regulations, make functional food an added value for the agri-food sector, given the economic impact of the commercialization of this type of product. In the literature, several works refer to the use of different parts of lupine such as whole grains and defatted flour, among others [5][6][7][8]. Lupin seed protein content is high (up to 44%) and of good quality, offering potential health benefits, and contributing to the sustainability of cropping systems [9][10][11].…”