نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه بهداشت مواد غذایی ، دانشکده دامپزشکی، دانشگاه شهیدچمران اهواز، اهواز، ایران
2 گروه بهداشت مواد غذائی، دانشکده دامپزشکی، دانشگاه شهید چمران اهواز، اهواز، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Plant sprouts are receiving a great deal of attention because of their abundance, bioavailability of components, and health benefits. Germinated legume seeds were the most common sprouts consumed in the human diet. Alfalfa (Medicago sativa) sprout is a valuable source of protein, fiber, minerals, vitamins (B vitamins), glucosinolate, and phenolic compounds. Alfalfa sprout is usually consumed as dehydrated leaves, powder, or dietary supplements in the form of tablets. Regarding nutritional values, alfalfa sprout powder (ASP) could act as a prebiotic agent. The present study aimed to investigate the nutritional values and in vitro prebiotic potential of ASP on two probiotic strains, namely Lactobacillus casei ATCC 393 and Bifidobacterium longum ATCC 55813. Also, the effects of fermentation of ASP by probiotics on polyphenolic content and antioxidant activity were investigated.
Materials and methods: Fatty acid composition, amino acid profile, and mineral content of ASP were determined using a gas chromatography-mass detector, amino acid analyzer, and inductively coupled plasma-optical emission spectrometry, respectively. ASP at two concentration levels of 0.5 and 1% was tested for its growth stimulation effect on two probiotics, L. casei and B. longum. Fructooligosaccharide (FOS) and glucose were used as standard prebiotic and control positive, respectively. The changes in probiotic populations and pH were monitored during 48 h fermentation in glucose-free MRS broth (GF-MRSB). The total phenolic content (TPC) and antioxidant activity of ASP were evaluated during fermentation using the Folin–Ciocalteu method and the DPPH radical scavenging assay.
Results: ASP contains high levels of aspartic acid, glutamic acid, and essential amino acids, including phenylalanine, leucine, and lysine. It also includes a high content of unsaturated fatty acids, including linoleic and oleic acids. Potassium was found to be the mineral with the highest composition, followed by phosphorus and calcium. Both probiotic strains could grow effectively in the presence of ASP. The cell numbers of L. casei and B. longum increased by 4.91 and 5.11 Log CFU/ml after 48 h fermentation of ASP-1%, which were comparable with the stimulatory effects of FOS and glucose. The pH decrease of GF-MRSB was negatively correlated with the concentration of ASP. Antioxidant activity and TPC increased continually during fermentation by both probiotics, with L. casei exhibiting a stronger impact.
Conclusion: Results demonstrated that ASP is an excellent source of minerals, essential amino acids, and unsaturated fatty acids. Probiotic bacteria not only survive in the presence of ASP but also increase polyphenolic content, thus enhancing the antioxidant activity and functional capacity of the fermented ASP. Fermenting phenolic compound-rich plant sprouts with probiotic bacteria can be considered a novel approach to the development of functional foods.
کلیدواژه‌ها [English]
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