Traditional Food-Processing and Preparation Practices to Enhance the Bioavailability of Micronutrients in Plant-Based Diets1

Abstract

Dietary quality is an important limiting factor to adequate nutrition in many resource-poor settings. One aspect of dietary quality with respect to adequacy of micronutrient intakes is bioavailability. Several traditional household food-processing and preparation methods can be used to enhance the bioavailability of micronutrients in plant-based diets. These include thermal processing, mechanical processing, soaking, fermentation, and germination/malting. These strategies aim to increase the physicochemical accessibility of micronutrients, decrease the content of antinutrients, such as phytate, or increase the content of compounds that improve bioavailability. A combination of strategies is probably required to ensure a positive and significant effect on micronutrient adequacy. A long-term participatory intervention in Malawi that used a range of these strategies plus promotion of the intake of other micronutrient-rich foods, including animal-source foods, resulted in improvements in both hemoglobin and lean body mass and a lower incidence of common infections among intervention compared with control children. The suitability of these strategies and their impact on nutritional status and functional health outcomes need to be more broadly assessed.

Fermentation and germination improve nutritional value of cereals and legumes through activation of endogenous enzymes

“…Unfortunately, it is also associated with proliferation of microorganisms such as yeast and molds that may cause food safety concerns (Omemu, 2011), reduction in provitamin A and antioxidant carotenoids (Ortiz, Nkhata, Buechler, Rocheford, & Ferruzzi, 2017), as well as loss of vitamins and minerals (Hotz & Gibson, 2007). …”

“…Tang and Zhao (1998) concluded that the PAL activity is enhanced during the process of germination. Another possible explanation is that there could be hydrolysis of bound phenolic compounds as well as de novo biosynthesis of phenols in the embryonic axis of the sprouts (Hotz & Gibson, 2007; Onyango et al., 2013; Zilic et al., 2015). The increased content of phytochemicals results into increased antioxidant activity of germinated cereals and legumes.…”

“…While these techniques are important in improving the shelf life, palatability, and transportability, they can also have adverse effects on the nutrient profiles of these foods. Overall, it appears that some techniques such as fermentation and malting can simultaneously reduce antinutritional factors and enhance nutrient availability (Hotz & Gibson, 2007). Since fermentation and germination are widely used for processing cereals and legumes which constitute a large part of diets for households in developing countries, here we provide a review of how these techniques influence nutrient content and availability.…”

Bioconversion of degraded husked sorghum grains to ethanol

“…Batch-2 substrates with higher sugars level tend to exert osmotic stress on cells than Batch-1 substrates [24,27,29]. Furthermore, the additional presence of lignin-derived phenolic compounds liberated during mashing (predominantly from husks materials) may further exacerbate environmental stress on P. stipitis cells [16,27,29,30]. KSV8 substrate consistently showed faster and higher fermentation rates in terms of CO 2 production by both S. cerevisiae and P. stipitis (Fig.…”

“…Interestingly, in spite of observed residual FAN, P. stipitis was unable to appreciably utilise available xylose. This may be reflective of the cells impaired fermentative capacity as ethanol concentration in the media increases [28][29][30].…”