Targeted metabolite profiling of pigeon pea (Cajanus cajan) seeds and, toward product (falafel) development
Date
2022-04
Authors
Journal Title
Journal ISSN
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Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Global food systems are currently under pressure, not only to meet the demand for food
production, but also toward diversifying our selection of crops based on their nutrient profile.
Furthermore, the effects of global warming are key contributors in reducing agricultural food
production. Food security issues have thus become an emergent future concern and the
United Nations have included nutrition as part of their sustainable development goals, with
SDG 2 speaking to equitable access of nutritious food. This has led to the belief that humanity
needs to consider investigating alternativ, or future fit, crop models to increase food and
nutrient production. Amongst a group of plants targeted are the pulses. They are harvested for
their seeds and, are nutritionally superior to the common cereal crops (rice, maize, and wheat)
which we currently rely on. Nutrients contributed by plants can be divided into primary and
secondary metabolites. Primary metabolites, such as starch, proteins and lipids, are sources of
energy for the human body, whereas secondary metabolites often display bioactive properties
which can be utilised for their therapeutic potential. This study sought to uncover some of the
basic aspects of primary and secondary metabolites present in pigeon pea seeds.
Apart from demonstrating the presence of resistant starch (a key driver in human gut
microbiome health), we investigated the secondary metabolite profile of the hull from a
pigeon pea line and, tentatively identified an array of therapeutically important metabolites
using LC-MS/MS and metabolite database searches. Amongst them were luteolin and
quercetin, also previously identified in pigeon pea. Furthermore, total antioxidant capacity
and DNA protection assays demonstrated that the pigeon pea seed, especially the hull, could
be considered as a functional health component of the crop, because of the presence of
numerous bioactive metabolites (albeit tentatively identified) potentially providing such
antioxidant capacity.
Despite the hull being removed during the processing of commercially available pigeon peas,
we set out to determine whether we could develop a food product with pigeon pea flour, and
to test for its quantitative and qualitative aspects using descriptive sensory analysis (DSA).
Pigeon pea flour was compared to that of chickpea as a falafel base. The pigeon pea flour
demonstrated stronger savoury-associated attributes (nutty, garlic, cumin, green, savoury,
salty) and texture profile analysis indicated that coarsely ground flour produces a moister, less
dense, and less hard falafel.
From the targeted metabolite analysis, there is motivation for further research and opportunity
for product development based on the health benefits the crop poses. The DSA demonstrated
that pigeon pea flour can be used to create a falafel, akin to that of chickpea. Depending on
future consumer panels, such falafels could use the outcomes of the DSA to make necessary
consumer-preferred flavour and aroma adjustments, and potentially successfully incorporate a
new crop into our current food systems.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.
Description
Thesis (MScAgric)--Stellenbosch University, 2022.
Keywords
Pigeon pea -- Seeds, Plants -- Effect of global warming on, Falafel, Descriptive sensory analyses, Antioxidants, Metabolites -- Therapeutic use, Pigeon pea -- Nutrition, Cajanus cajan -- Breeding, UCTD