Impact of Processing on Physical, Chemical and Pasting Properties of Tamarind (T. indica) Seed Flour

Abstract

Tamarind seed is a discarded waste material from the tamarind pulp industry. The seed contains plethora of nutrients, however its application as food ingredient in Nigeria is limited. This study investigated the impact of processing techniques on physical (colour), proximate, mineral, anti-nutrient and pasting properties of tamarind seed flour using standard methods. Unprocessed seeds (sample A) served as the control, soaked seeds (sample B), roasted seeds (sample C) and autoclaved seeds (sample D). The obtained flour samples were analysed for the physical (colour), proximate, mineral, anti-nutrient and pasting properties using standard methods. Colour values (L*) of seed flour decreased whereas a* and b* values increased in processed flours compared to the control. Raw and processed tamarind seed flours are composed mainly of carbohydrate (65.0-75.2%) and protein (2.3-12.7%) with minuscule quantities of dietary fibre (3.50-7.10%), fat (5.4-6.8%) and ash (1.25-2.08%). The results revealed the following ranges in mineral concentrations: calcium (11.72-18.76mg/100g), magnesium (125.48-152.55mg/100g), potassium (224.49-487.37mg/100g) and iron (22.34-31.04mg/100g). Boiling, autoclaving and roasting significantly (p≤0.05) altered the anti-nutritional contents of tamarind seeds. There exist variation in the pasting viscosities with the control and processed tamarind flours being significantly different (p≤0.05).  The study highlighted that roasting of the seeds could eliminate the anti-nutrients and improved the quality of seeds compared to soaking and autoclaving processes. Exploring the potential of tamarind seeds for human consumption will clearly reduce the over-dependence on common legumes as protein source in marginalised communities.