Potential prebiotic effect of hydrated basil seeds (Ocimum basilicum L.) and hydrated chia seeds (Salvia hispanica L.) after in vitro gastrointestinal digestion

Basil seeds and chia seeds are commonly consumed as drink and food. Basil and chia are part of the Lamiaceae family. They have a hard inner part and an outer layer with pectin fibrils. When the outer pericarp of the seed is soaked in water, it will swell until it forms gum. Both basil and chia seeds are similar in physical characteristics – they are black, oval, and nearly the same size. Hydrated basil seeds (HBS) and hydrated chia seeds (HCS) have rarely been studied for their prebiotic potential in vitro . This study aimed to determine the prebiotic potential of both hydrated basil seeds and hydrated chia seeds, based on their chemical characteristics, carbohydrate resistance during simulated gastrointestinal (GI) digestion, prebiotic index and prebiotic activity using Lactobacillus paracasei (probiotic) and Escherichia coli (pathogenic). The initial step of this study was the chemical characterization of both HBS and HCS. The second step was to evaluate the carbohydrate resistance of both HBS and HCS in simulated gastrointestinal digestion by analyzing the reducing sugar content and the total carbohydrate content after GI digestion. The third step was determining the prebiotic index and prebiotic activity by testing the growth of colonic bacteria ( L. paracasei and E. coli ) to which HBS and HCS were added at 2.5, 5, and 10% (v/v). The results showed that lipid and protein content in HBS and HCS was quite high, with HCS having higher levels than HBS. Both HBS and HCS contained carbohydrates that resist hydrolysis by human digestive enzymes, with HCS containing a higher percentage of hydrolyzed carbohydrates (22%) compared to HBS (11%). Furthermore, HCS was found to stimulate the growth of L. paracasei to a greater extent than HBS. HCS 2.5% demonstrated the highest prebiotic index, even higher than inulin 2.5% as a positive control. HCS was more discerning in promoting the growth of colon bacteria compared to HBS. Based on prebiotic criteria, this study found that hydrated chia seeds (HCS) were more effective as prebiotic than hydrated basil seeds (HBS).