Writing in Food Science and Technology, researchers from universities in Spain, Argentina and its National Scientific and Technical Research Council (CONICET), conducted a comparative study looking at the functional components of pomegranate and jacaranda seeds – both high in conjugated linolenic acids (CLnAs) yet “poorly used in food development”.
(Conjugated linolenic acids (CLnAs) should not be confused with conjugated linoleic acids (CLA).)
'Most important compounds to be considered'
The researchers said consumers were “continuously demanding” healthier foods or products with more functional properties, particularly those avoiding excessive fats, meaning the search for healthy ingredients was highly relevant.
“The lipid contents and the types of fatty acids (FAs) represent the most important compounds to be considered before food consumption. Thus, the production of dairy foods enriched in n-3 or n-6 FAs is continuously growing in the industry, and natural sources, such as uncommon oils, plant extracts or nuts, are usually incorporated for food fortification,” the researchers wrote.
Pomegranate seeds, for example, were often discarded as waste by-product in the manufacture of juices or when consumed as a fresh fruit yet contained “valuable pharmaceutical and nutritional compounds”, they said, like conjugated fatty acids and phenolics. Similarly, jacaranda seeds also contained CLnAs but its composition and promise in food remained “unexplored”.
“In the present work, a comparative study was performed focusing on the nutritional and fatty acid composition of pomegranate seeds and jacaranda seeds, as well as the biotechnological potential for their use as additives for yogurt manufacture,” the researcher wrote.
Improved fatty acid profile
Findings from the comparative study showed both fruit seeds could be “potential sources” of CLnAs and used as food ingredients, with jacaranda seeds presenting “a unique naturally available” source of jacaric acid for human consumption and pomegranate punicic acid as its predominant CLnA.
Total CLnA content was two-fold higher in pomegranate seed oil than jacaranda seed oil, but both exhibited high UFA levels and low saturated fatty acid content. MUFA content was higher in jacaranda seed oil than pomegranate seed oil.
The researchers said inclusion at a 0.5% minimum rate of both seeds in powder form “improved the fatty acid profile and DPPH activities of the fermented products and maintained good nutritional, microbiological and sensorial characteristics”. When used at this inclusion rate, they said yogurt manufacturers could achieve CLnA levels of 2g / 100g FAME [fatty acid methyl ester].
“...The healthy fatty acid profile of fortified yogurts herein, plus the great CLnA contents offered by these products, is a technological alternative with remarkable health benefits.”
The inclusion of the seed powders also kept total lipid content near 13g per 100g serve of yogurt, meaning manufacturers could develop fortified yogurts still classified as 'low fat', the researchers said. Worth noting was that, from a taste and color standpoint, pomegranate was preferred among consumers, they added.
'Must be taken as a starting point...'
“To our knowledge, this is the first study focused on the development of CLnA-enriched yogurt by the addition of seed flour and must be taken as a starting point for production of new functional fermented products. Thus, pomegranate and jacaranda seed and seed oil might have wide biotechnological applications as nutraceuticals or food ingredients,” the researchers concluded.
They said the next step would be conducting studies to confirm consumption and daily dosing promoted beneficial health effects, as would be the case when working with any other medicinal plant.
Source: Food Science and Technology
Published online ahead of print, doi: 10.1016/j.lwt.2019.05.045
Title: “Comparative study of pomegranate and jacaranda seeds as functional components for the conjugated linolenic acid enrichment of yogurt”
Authors: CPV. Nieuwenhove et al.