Effect of microbial inoculants on bioactive compounds and antioxidant activity of xcat'ik pepper (Capsicum annuum L.)

Xcat'ik pepper (Capsicum annuum L.), native to the Yucatan Peninsula, has unique organoleptic properties. However, the nutraceutical quality of the fruit has been scarcely explored and only a few previous studies have focused on improving the productive yield of the plant, hence the importance of generating knowledge in this field. The Capsicum species is considered an important food due to the bioactive compounds content, which promote beneficial health effects. The use of microbial inoculants is an alternative to increase yield, improve fruit quality, and reduce the use of chemical fertilizers. In this work, the effect of a microbial consortium, as well as Bacillus subtilis and Trichoderma harzianum on the contents of ascorbic acid, total phenols, flavonoids, chlorophylls, carotenoids, antioxidant capacity and capsaicinoids in the fruit of xcat'ik pepper was evaluated. The obtained results were compared with an uninoculated control. Inoculations with T. harzianum and B. subtilis increased carotenoid content as well as antioxidant activity by ABTS(+), in contrast the microbial consortium increased antioxidant activity by DPPH. According to our results, the evaluated inoculants could replace chemical fertilizers, because they equal or even improve the nutraceutical quality of the x'catik pepper fruit, with the advantage of being less harmful to the environment.