Characterizing quality traits of boiled yam: texture and taste for enhanced breeding efficiency and impact

Abstract

BACKGROUND: Boiled yam key quality attributes typical for West African consumers are: crumbly, easy to break, and sweet taste. New yam varieties are being developed but high or medium throughput tools to assess the required quality traits and their range of acceptance are limited. This study assessed the acceptance thresholds of these quality attributes and established the predictive models for screening yam varieties that meet the required consumers' preferences. RESULTS:Overall liking was associated with sweet taste, crumbly and easy to break (r values 0.502, 0.291 and -0.087, respectively). These parameters and selected biophysical parameters highly discriminated the boiled yam varieties. Crumbly texture and easy to break were wellpredicted by penetration force and dry matter, whereas sweet taste by dry matter and sugar intensity. A high crumbliness and sweet taste are preferred (sensory scores above 6.19 and 6.22 for crumbly and sweet taste, respectively, on a 10 cm unstructured line scale), while a too high easiness to break is disliked (sensory scores ranging from 4.72 to 7.62). Desirable biophysical targets were between 5.1 and 7.1 N for penetration force, dry matter around 39% and sugar intensity below 3.62 g/100g. Some improved varieties fulfilled the acceptable thresholds, and the screening was improved through the deviation from optimum. CONCLUSION:The acceptance thresholds and the deviation from optimum for boiled yam assessed through the instrumental measurements are promising tools for yam breeders.

Varietal and environmental influences on organoleptic and cooking quality of water yam (Dioscorea alata) landraces

“…[18][19][20][21][22][23] It has been shown that in D. alata a good eating quality combines high DM and starch contents. 19,24 The decline in DM content in the boiled pulp as compared to the raw samples was also reported by Adinsi et al 17 and is probably due to water absorption. 16 Crude protein content varied from 63 to 94 g kg −1 , which is in good agreement with the range of 45-99 g kg −1 , 25 and 51-110 g kg −1 , 23 recorded in water yam in West Africa.…”

“…Water absorption can be considered an indicator of chewiness ( r = 0.43). Similarly, Adinsi et al 17 . obtained a significant negative correlation between hardness determined using a texturometer and friability (crumbliness) assessed by sensory analyses ( r = −0.94) in boiled water and white yam.…”

“…The value of the latter is within the range of 58.8-88.8% reported in new hybrids of D. alata by Njoh Ellong et al 26 Results thus indicated that cooking quality, textural properties and chemical composition varied widely with variety. Textural properties depend on the variety as recorded in D. alata and D. rotundata 17 and in cassava. 27 Egesi et al 28 also found a large variability in quality traits intra D. alata, mainly for color and sensitivity to browning (oxidation).…”

“…Easy to peel, quick cooking, texture linked to a crumbly pulp, light color (white-cream or yellow) and low sensitivity to browning when cut are considered desirable quality traits in boiled water yam. 9,17,24,28,31 In the current study, we characterized only varieties appreciated by producers and consumers. Cooking time was between 13 and 23 min.…”

Contrasting effects of polysaccharide components on the cooking properties of roots, tubers and bananas

“…Theoretically, hardness should increase with DM of RTB samples because water can plasticize the system. It is largely observed in pasty products, such as in pounded yam, 21 but positive correlations were only found between DM of raw samples and the hardness of boiled yam (as already reported 58,59 ) and fried (see Supporting information, Fig. S3) and boiled plantain.…”