Effect of Boiling and roasting on lipid quality, proximate composition, and mineral content of walnut seeds (Tetracarpidium conophorum) produced and commercialized in Kumba, South‐West Region Cameroon

Abstract

The effect of boiling and roasting on the lipid quality, proximate composition, and mineral content of African walnut seeds (Tetracarpidium conophorum) was assessed. Results indicated that the quality of walnut oil significantly (p < .05) reduces with the treatments. Oils extracted from DBWN 60 min (Dried and boiled walnuts 60 min) and FBWN 60 min (Boiled fresh walnuts 60 min) were the most altered. The proximate composition and mineral content of walnut seeds was also significantly affected (p < .05) by the treatments. This study reveals that, thermal processing has significant effects on the nutrients and quality of lipids of walnut oil. DTRWN 60 min (Dried and traditionally roasted walnuts 60 min), DORWN 60 min (Dried and oven roasted walnuts 60 min), and TRFWN 30 min (traditionally roasted fresh nuts 30 min) are the best methods for cooking walnut because they preserve the quality of its lipids and some of the nutrients.

Nutritional diversity in accessions of African walnut (Plukenetia conophora L.) sourced from southwestern Nigeria as influenced by collection center and processing

“…The value for phosphorus in this study was higher in boiled nuts than in fresh nuts contrary to the report of Djikeng et al (2017) who reported a decrease in phosphorus concentration (between 16.86 and 22.38 mg/100g) in all the cooked samples. The result obtained in this study was higher than 35 mg/100g previously reported by Nwaoguikpe et al (2012).…”

“…Boiling boosted the amount of iron in walnut and this indicated that, boiling for 60 minutes as was done in this study was suitable for the release of iron in walnut seeds. This result agrees with the report of Djikeng et al (2017) that higher values of iron were obtained in boiled nuts than in the raw nuts (28.81 and 20.84 mg/100g, respectively). The amount of iron provided by walnut can help alleviate or prevent nutritional anemia associated with iron deficiency.…”

“…The amount of iron provided by walnut can help alleviate or prevent nutritional anemia associated with iron deficiency. Although the amounts of potassium and sodium decreased in values during boiling compared to fresh nut, their concentrations were higher than 625 and 26 mg/100g reported by Ayoola et al (2011) and Djikeng et al (2017), respectively. The minerals in African walnut are beneficial to human health due to their direct relationship with hypertension in human.…”

“…The decrease in the quantity of magnesium in boiled nut could be attributed to the loss of this mineral during processing through the diffusion process. The amount of magnesium obtained in this study was higher than 171.12 mg/100g as previously reported by Ayoola et al (2011) and Djikeng et al (2017) in walnut.…”

Effect of roasting on the chemical composition, functional characterisation and antioxidant activities of three varieties of marble vine (Dioclea reflexa): An underutilised plant

“…It is one of the most common processing methods used in Africa and this helps to improve the functional properties of food products [ 7 ]. The application of dry heat to food facilitate browning reaction thereby improving the nutritional property of leguminous seeds [ 8 ]. Although heat treatment has been reported to boost the antioxidant property of foods [ 9 , 10 ], it could cause significant changes to product quality when heated at high temperature.…”