Effect of acid catalyst on pyroconversion of breadfruit (Artocarpus altilis) starch: Physicochemical and structural properties

Authors: OLIVEIRA, E - University Of Fortaleza (UNIFOR); LOVERA, MIGHAY - Central University Of Venezuela; PIRES, V - University Of Fortaleza (UNIFOR); MENDES, F - State University Of Ceará; MAIA, N - State University Of Ceará; RODRIGUES, J - Universidade Federal Do Ceara (UFC); BASTOS, M - Embrapa; Cheng, Huai; Biswas, Atanu; MOREIRA, R - University Of Fortaleza (UNIFOR); MOREIRA, A - University Of Fortaleza (UNIFOR)

Submitted to: Journal of Food Processing and Preservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2022
Publication Date: 3/21/2022
Citation: Oliveira, E.D.S., Lovera, M., Pires, V.R., Mendes, F.R.D.S., Maia, N.V.L.P., Rodrigues, J.P.V., Bastos, M.D.S.R., Cheng, H.N., Biswas, A., Moreira, R.D.A., Moreira, A.C.D.O.M. 2022. Effect of acid catalyst on pyroconversion of breadfruit (Artocarpus altilis) starch: Physicochemical and structural properties. Journal of Food Processing and Preservation. 43(3). Article e16408. https://doi.org/10.1111/jfpp.16408.
DOI: https://doi.org/10.1111/jfpp.16408

Interpretive Summary: After cellulose, starch is the most abundant polysaccharide in plant cells. It is often modified to enhance its performance in different applications. One type of modification is pyrodextrinization, involving the use of heat or heat with an acid catalyst. In view of the fact that the tropical breadfruit may be an excellent unconventional source of starch, we have extracted starch from breadfruit and produced pyrodextrins using hydrochloric and acetic acids. We have characterized these pyrodextrins with a number of analytical methods and found some interesting properties. Because the pyroconversion process is fairly straightforward, these pyrodextrin may be promising functional ingredients for food applications in the future.

Technical Abstract: This work aimed to produce pyrodextrins from breadfruit starch (Artocarpus altilis) and evaluate the effect of two mineral acids (HCl and glacial acetic acid) as catalysts for pyroconversion on specific physicochemical and structural properties of pyrodextrins. Pyroconversion was performed by spraying the acid solution over the powdered starch (final acid/starch ratio 1.82 g acid/kg of starch on a dry basis) and then heated in an oven at 140 °C for 180 min. The pyrodextrins obtained were analyzed for proximate composition, dextrose equivalents (ED), color difference ('E), solubility in water at 25°C, pH, intrinsic viscosity, infrared (IR) spectroscopy, and granule morphology by scanning electron microscopy (SEM), and the data were compared to native starch. Pyroconversion caused a reduction (p<0.05) in ash levels but did not affect the protein content. Pyrodextrin made with HCl showed higher ED, 'E and solubility in water and lower viscosity than native starch (p<0.05), suggesting significant hydrolysis during starch pyroconversion. The IR spectra of pyrodextrins showed a reduction in the 1647 cm-1 region, attributed to decreased a (1,4) bonds, corroborating the presence of hydrolysis reactions. Some damaged granules were seen in the SEM images, but the size and shape were similar to the native granules. The use of acetic acid was considered a milder treatment, and it caused a slight increase in the total and soluble fiber contents, which can be advantageous for the production of soluble and less viscous dietary fibers for food applications.