Vet World   Vol.16   April-2023  Article-19

The effects of heat-moisture treatment on resistant starch levels in cassava and on fermentation, methanogenesis, and microbial populations in ruminants

Background and Aim: Resistant starch (RS) is difficult to digest in the digestive tract. This study aimed to evaluate the effects of heat-moisture treatment (HMT) on RS in cassava and examined its impact on rumen fermentation.

Materials and Methods: Cassava flour was used as a raw material and used in a randomized block design with four different cycles of HMT as the treatments and four different rumen incubations in vitro as blocks. Treatments included: HMT0: without HMT (control), HMT1: one HMT cycle, HMT2: two HMT cycles, and HMT3: three HMT cycles. Heat-moisture treatment processes were performed at 121°C for 15 min and then freezing at -20°C for 6 h. Analyzed HMT cassava starch characteristics included components, digestibility, and physicochemical properties. In in vitro rumen fermentation studies (48 h incubation) using HMT cassava, digestibility, gas production, methane, fermentation profiles, and microbial population assessments were performed.

Results: Heat-moisture treatment significantly reduced (p < 0.05) starch, amylopectin, rapidly digestible starch (RDS), and slowly digestible starch levels. In contrast, amylose, reducing sugars, very RDS, RS, and protein digestion levels were significantly increased (p < 0.05). Additionally, a reduced crystallinity index and an increased amorphous index were observed in starch using Fourier-transform infrared analyses, while a change in crystalline type from type A to type B, along with a reduction in crystallinity degree, was observed in X-ray diffraction analyses. Heat-moisture treatment significantly (p < 0.05) reduced rumen dry matter (DM) degradation, gas production, methane (CH4 for 12 h), volatile fatty acid (VFA), and propionate levels. In addition, acetate, butyrate, and acetate/propionate ratios, as well as population of Streptococcus bovis and Bacteroides were significantly increased (p < 0.05). However, pH, ammonia, and organic matter digestibility were unaffected (p < 0.05) by HMT.

Conclusion: Cassava HMT altered starch characteristics, significantly increased RS, which appeared to limit rumen digestion activity, decreased rumen DM degradation, gas production, VFAs, and CH4 production for 12 h, but increased S. bovis and Bacteroides levels. Keywords: heat-moisture treatment, in vitro, rumen fermentation, starch modification.

Keywords: heat-moisture treatment, in vitro, rumen fermentation, starch modification.

How to cite this article: Putra LO, Suharti S, Sarwono KA, Sutikno S, Fitri A, Astuti WD, Rohmatussolihat R, Widyastuti Y, Ridwan R, Fidriyanto R, and Wiryawan KG (2023) The effects of heat-moisture treatment on resistant starch levels in cassava and on fermentation, methanogenesis, and microbial populations in ruminants, Veterinary World, 16(4): 811-819.

Received: 14-01-2023  Accepted: 06-03-2023     Published online: 20-04-2023

Corresponding author:    E-mail: sri_suharti@apps.ipb.ac.id

DOI: 10.14202/vetworld.2023.811-819

Copyright: Putra, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.