Viability of lactic acid bacteria microencapsulated by spray drying with malanga starch in two dietary supplements

Abstract

Malanga corms are an underground stem with a high nutritional value as it contains carbohydrates and proteins, in addition to being highly digestive; The starch extracted from them can be used in the encapsulation of probiotic microorganisms, which are of great importance for human health. The objective of this work was to develop a food supplement with functional characteristics, added with lactic acid bacteria (Lactobacillus casei) (LAB), using malanga (Xanthosoma sagittifolium) starch. The supplement was obtained by mixing 150 mL of cooked fruit pulp (mango or apple) with 400 mL of sweet whey (pH of 6.0), at a temperature of 45 ± 1 °C until the desired consistency (449.9 mPas/s at a temperature of 25 °C) was achieved. Subsequently, 1 % or 2 % of malanga starch (p/v) and 10 mL of probiotic cultures were added per each 100 mL of mixture. it was then dehydrated at 80 ºC and 150 °C with an air flow of 20 mL/min for apple and 8 mL/min for mango by spray drying. The yield was 12 %, with viability of LAB in the dehydrated supplement at 3 months of storage higher than 1 x 10⁸ CFU/g. The absence of coliform bacteria, as well as Salmonella and Shigella, indicate that the supplements are safe and suitable for consumption. The nutritional composition of the apple supplement was 2.23 % fiber, 5.93 % fat, 4.95 % protein and 79 % carbohydrates; the mango supplement content was 0.59 % fiber, 7.6 % fat, 4.2 % protein and 80.20 % carbohydrates. The malanga starch allowed the LAB microencapsulation and the maintenance of their viability during the storage of sweet whey and fruit-based food supplements.