Effect of drying method on the production of in vitro short‐chain fatty acids and histone deacetylase mediation of cocoa pod husk

Abstract

We evaluated the effect of cocoa pod husk (CPH) processing (microwave [MW], forced-air drying [FAD], and FAD plus extrusion [FAD-E]), and in vitro gastrointestinal digestion on the in vitro human colonic fermentation metabolism, in vitro bioactivity on human HT-29 colon cancer cell, and the in silico mechanism of selected compounds. CPH as a substrate for human colonic microbiota significantly decrease local pH (MW −0.7, FAD −0.2, and FAD-E −0.3, 24 h) and modifies their metabolic activity (short-chain fatty acids[SCFAs] production). FAD-E generated the highest butyric (7.6 mM/L, 4 h) and FAD the highest acetic and propionic acid levels (71.4 and 36.7 mM/L, 24 h). The in vitro colonic fermented FAD-E sample (FE/FAD-E) caused HT-29 colorectal cancer cells death by inducing damage on membrane integrity and inhibiting (up to 92%) histone-deacetylase (HDAC) activity. In silico results showed that chlorogenic acid, (−)-epicatechin, and (+)-catechin, followed by butyric and propionic acids, are highly involved in the HDAC6 inhibitory activity. The results highlight the potential human health postbiotic benefits of CPH consumption, mediated by colonic microbiota-derived metabolites. K E Y W O R D Scocoa pod husk, in vitro colonic fermentation, in vitro gastrointestinal digestion, histone deacetylase, human colon cancer cells, postbiotic Practical Application: The enormous amount of CPH (10 tons/1 ton of dry beans) generated by the cocoa industry can be used as a removable source of bioactive compounds with physicochemical functionality and health bioactivity. However, their potential applications and health benefits are insufficiently explored. CPH represents a serious disposal problem; practical and innovative ideas to use this highly available and affordable material are urgent. Research exploring their potential applications can increase the sustainability of the cocoa agro-industry. This paper highlights the value addition that can be achieved with this valuable industrial co-product, generating new functional products and ingredients.

High potential extracts from cocoa byproducts through sonotrode optimal extraction and a comprehensive characterization

“…Among the bioactive compounds with the greatest presence are theobromine (764 to 9028 mg/kg), caffeine (150 to 3370 mg/kg), epicatechin (4 to 748 mg/kg), catechin (12 to 180 mg/kg), and other minor compounds such as procyanidin type A and type B [6] . In the CPH of CCN51 genotype, around 111 mg/g of phenolic compounds have been found, and the antioxidant activity using the ABTS radical was 155 µmol of Trolox equivalent per grams of sample [3] .Recently, in an in silico study, it has been reported that epicatechin and catechin from CPH are highly associated with the inhibitory activity of histone deacetylase 6 in HT-29 colorectal cancer cells [7] , and epicatechin has also been shown to promote the inhibition of fibroblast growth factor receptor 3 (FGFR3) gene signalling pathways by inducing changes in elongation primary cilium of chondrocytes and promote femur lengthening [8] .…”