Influence of drying methods on heavy metal composition and microbial load of plantain chips

Abstract

Mature unripe plantain is usually processed into chips using the traditional sun-drying method without considering consumer safety. Thus, there is a need to assess the influence of solar tent and open sun drying on the heavy metal composition and microbial load of plantain chips. Thirty samples of dried plantain chips were collected randomly from 10 processing centers in Akure South and Idanre Local Government Areas of Ondo State, Nigeria. In addition, four popularly consumed plantain varieties (agbagba, bobby tannap, mbi egome, and pita 23) were processed to chips and dried using open sun and solar tent drying. The samples were analyzed for heavy metal compositions using an Inductively Coupled Plasma- Optical Emission Spectrometer (ICP-OES) and microbial loads using the serial dilution method. The heavy metal content of the dried plantain chips was in the range of 0.01–0.08 mg/kg for Cd, 0.01–0.07 mg/kg for Co, and 0.05–0.50 mg/kg for Pb. Seven fungi (Penicillium spp., Rhizopus spp., Aspergillus flavus, Aspergillus Niger, Aspergillus tamarii, Fusarium verticillioides, and Monilla spp.) of health importance were isolated. The drying methods had a significant effect on the Cd (p < 0.01), Co (p < 0.001), and Pb (p < 0.01) contents of the plantain chips, but with no significant effect (p > 0.05) on the bacterial, fungi, and total coliform counts. Since the heavy metal content and microbial loads were higher in the surveyed and open sun-dried samples, the solar tent-dryer may be more reliable in producing less contaminated plantain chips than the open sun drying methods.

Keywords:

• Plantain chips
• alternative drying
• contamination
• consumer safety

PUBLIC INTEREST STATEMENT

Mature unripe plantain is usually processed into dried chips using the traditional sun-drying method without considering the safety of the consumers through product contamination. It is envisaged that the solar tent-dryer may reduce microbial and heavy metals contamination of plantain chips. The information provided in this article may be of use to dried plantain chip processors in the production of contaminant-free products, and whose safety will be better than the open-sun dried plantain chips.

Acknowledgements

The authors would like to acknowledge the Food and Nutrition Sciences laboratory of the International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria, for the support. The support of the construction of the solar tent dryer by Engr. Diallo Thierno of IITA is highly appreciated.

Author contributions

Conceptualization, all authors.; methodology, A.A.A., W.A. and A.B.A.; formal analysis, A.A.A, W.A. and B.M.D.; investigation, A.A.A and W.A.; resources, B. M. D.; data curation, A.A.A and W.A.; writing—original draft preparation, A.A.A. and W.A.; writing—review and editing, all authors; supervision, W.A., A.B.A. and B.M.D.; funding acquisition, B.M.D. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

All data will be deposited into the IITA data repository and can be accessed through http://data.iita.org. The data will also be made available on request from the corresponding author.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/23311932.2022.2113205

Additional information

Funding

This research was supported by the CGIAR on Roots, Tubers and Bananas (RTB) Project.

Notes on contributors

Ayodele Adenitan

Ayodele Adenitan (MSc) was a Graduate Research Fellow in the Food and Nutrition Sciences Laboratory of the IITA, Ibadan, Oyo State, Nigeria. Awoyale Wasiu (PhD) is a Lecturer in the Department of Food Science and Technology, Kwara State University, Malete, Kwara State, Nigeria, and a Postharvest Specialist (Consultant) in the Food and Nutrition Sciences Laboratory of the International Institute of Tropical Agriculture (IITA), Ibadan, Oyo State, Nigeria. Aisha B. Akinwande (PhD) is a Professor of Food Science in the Department of Food Science, Ladoke Akintola University of Technology Ogbomoso, Nigeria. Busie Maziya-Dixon (PhD) is a Senior Food and Nutrition Scientist and Head of the Food and Nutrition Sciences Laboratory of IITA, Ibadan, Nigeria. The outcome of this study will assist the dried plantain chip processors in reducing microbial and heavy metal contamination of the product.