Predicting quality, texture and chemical content of yam (Dioscorea alataL.) tubers using near infrared spectroscopy

Abstract

Despite the importance of yam ( Dioscorea spp.) tuber quality traits, and more precisely texture attributes, high-throughput screening methods for varietal selection are still lacking. This study sets out to define the profile of good quality pounded yam and provide screening tools based on predictive models using near infrared reflectance spectroscopy. Seventy-four out of 216 studied samples proved to be moldable, i.e. suitable for pounded yam. While samples with low dry matter (<25%), high sugar (>4%) and high protein (>6%) contents, low hardness (<5 N), high springiness (>0.5) and high cohesiveness (>0.5) grouped mostly non-moldable genotypes, the opposite was not true. This outline definition of a desirable chemotype may allow breeders to choose screening thresholds to support their choice. Moreover, traditional near infrared reflectance spectroscopy quantitative prediction models provided good prediction for chemical aspects (R2 > 0.85 for dry matter, starch, protein and sugar content), but not for texture attributes (R2 < 0.58). Conversely, convolutional neural network classification models enabled good qualitative prediction for all texture parameters but hardness (i.e. an accuracy of 80, 95, 100 and 55%, respectively, for moldability, cohesiveness, springiness and hardness). This study demonstrated the usefulness of near infrared reflectance spectroscopy as a high-throughput way of phenotyping pounded yam quality. Altogether, these results allow for an efficient screening toolbox for quality traits in yams.

Detecting the genetic variants associated with key culinary traits inDioscorea alata

“…However, emerging tools now empower more efficient dissection of the culinary quality (https://rtbfoods.cirad.fr/). Recent advancements in near-infrared spectroscopy have shown promise in rapidly predicting quality traits such as texture and biochemical composition in yams, which can significantly accelerate breeding programs and enhance food security [7][8][9].…”

“…Moldability, or poundability, refers to the ability of cooked yam to be pounded or mashed into a desired consistency [7, 18]. It is a desirable trait for traditional dishes like pounded yam in West Africa, where yam is traditionally pounded with a mortar and pestle [19].…”

“…Unfortunately, interbreeding between these species is challenging due to cross-incompatibility [33]. Within D. alata , there has been observed a diversity in culinary quality, as documented in studies like Ehounou et al [7, 34]. Consequently, further genetic investigations focusing on the underlying genetic factors governing culinary quality traits in D. alata are necessary.…”

“…To cook the tubers, three identical pressure cookers (Moulinex) with 3L capacity and basic kitchen utensils were employed. The method described by Ehounou et al [7] was followed. First, the head and the tail were removed.…”

“…Recent research demonstrates the potential of NIRS analysis on raw tubers or flours for rapid, nondestructive evaluation of breeding populations[7,[77][78][79]. Integrating NIRS-enabled phenotyping into selection pipelines could greatly increase genetic gains for culinary quality.…”