Drying characteristics, nutritional and anti-nutritional properties of locust bean seed

Abstract

The need to ensure availability of locust beans when off-season forms the basis of this study. The study investigated the drying characteristics, nutritional composition and some anti-nutritional contents of dried locust beans. Fermented locust beans were dried at 50°C, 60°C, 70°C and 90°C. The moisture contents of the fermented locust seeds were determined at different time intervals between 0 and 480 min. Lower moisture content was achieved in a shorter drying time at higher temperature. The dried locust bean samples had lower moisture contents (12.36–12.76%) compared to control sample (38.76%). Higher drying temperature resulted in low ash content of the samples but increased the fibre, fat and protein content of the samples. The dried samples had low mineral contents compared to the fresh sample, which was used as control. The most abundant mineral in the samples were found to be calcium and zinc. No significant difference was observed in the titratable acidity and the pH of the locust bean samples at varying drying temperature. Increase in temperature resulted to a reduction in the antioxidant, phenolic composition and the anti-nutritional properties of the dried locust bean samples. Panelists preferred samples dried at lower temperature (50°C and 60°C compared with the samples dried at high temperature. The study concluded that locust bean should be dried using a carefully selected temperature to avoid negative impacts on the nutrients of the beans.

Keywords:

• locust beans
• anti-nutritional factor
• antioxidant properties
• sensory properties
• mineral composition
• drying properties

PUBLIC INTEREST STATEMENT

Inadequate post-postharvest storage facilities in many African countries have increased the need to apply drying techniques as a way of preserving the perishable crops. Locust beans is a condiment of choice by many Africans, and it is expedient to ensure its availability all the year round. In drying the condiment, it is necessary to ensure that the nutrients are not adversely affected. The aim of this work is therefore to investigate the best drying temperature for the locust beans while still minimizing the nutrient loss.

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgments

The authors appreciate Miss Omotayo Christianah for assisting in collecting the data for the research.

Additional information

Notes on contributors

Akinsola A. Famuwagun

Akinsola A. Famuwagun is a research scholar and a university lecturer at the Department of Food Science and Technology, Osun State University, Osogbo, Osun State, Nigeria. His specializes in Food Chemistry/Food analysis and Food Biochemistry. He has well above 20 research articles in national and international publishing outlets and has attended many academic conferences.

Kehinde A. Taiwo

kehinde A. Taiwo is a Professor of Food engineering in the Department of Food Science and Technology, Obafemi Awolowo University, Ile-Ife, Nigeria. She has published over 100 research articles with many book chapters in both national and international outlet. She has also attended many national and international academic conferences.