Evaluation of Physicochemical Properties of South African Cashew Apple Juice as a Biofuel Feedstock

Abstract

Cashew apple juice (CAJ) is one of the feedstocks used for biofuel production and ethanol yield depends on the physical and chemical properties of the extracted juice. As far as can be ascertained, information on physical and chemical properties of South African cashew apple juice is limited in open literature. Therefore, this study provides information on the physical and chemical properties of the South African cashew apple juice. Physicochemical characteristics of the juice, such as specific gravity, pH, sugars, condensed tannins, Vitamin C, minerals, and total protein, were measured from a mixed variety of cashew apples. Analytical results showed the CAJ possesses specific gravity and pH of 1.050 and 4.52, respectively. The highest sugars were glucose (40.56 gL−1) and fructose (57.06 gL−1). Other chemical compositions of the juice were condensed tannin (55.34 mgL−1), Vitamin C (112 mg/100 mL), and total protein (1.78 gL−1). The minerals content was as follows: zinc (1.39 ppm), copper (2.18 ppm), magnesium (4.32 ppm), iron (1.32 ppm), sodium (5.44 ppm), and manganese (1.24 ppm). With these findings, South African CAJ is a suitable biomass feedstock for ethanol production.

Physical, chemical, textural, and thermal properties of cashew apple fruit

“…The specific gravity value (1.057) was found to be lower than that of the average value of other similar fruits (1.069) reported by Deenanath et al (); Attri and Singh (); and Akinwale, Olubamiwa, and Ajav (). The primary reason may be because of the difference in ripening stages, location, varieties, and so on).…”

“…Ascorbic acid is one of the major organic acid present in cashew apple and the sample was found to have a higher value (218.933 mg/100 g) as compared to that of the cashew apple of other varieties studied by Deenanath et al () and Talasila, Vechalapu, and Shaik (). A similar trend of results was found for titratable acidity (0.423%) as reported by the above two researchers.…”

“…It is found that a numerous number of research literature on different physical, mechanical, thermal, textural, and biochemical properties of cashew nuts are available to us. However, research on these properties for cashew apple fruits are very scarce and hence needs proper research (Deenanath, Rumbold, Daramola, Falcon, & Iyuke, ). Therefore, the main focus of this research is to explore the major physical, thermal, textural, or mechanical and physicochemical properties of the cashew apple fruit to establish strong research information on this fruit.…”

Challenges and opportunities toward sustainable consumption and value addition of cashew apples in Tanzania

“…Cashew apples are used to process a number of value added products such as juice, wine, jam, pickles, and ethanol (David and Prasad, 2015; Runjala and Kella, 2017). In Sub-Saharan Africa, processing of cashew apples into products such as juice (Akinwale, 2000; Gyedu-Akoto, 2011), jam (Gyedu-Akoto, 2011), wine (Ogunjobi and Ogunwolu, 2010), ethanol (Deenanath et al, 2015) and cashew fiber (Adegunwa et al, 2020) has been studied. Strangely enough, there are few studies on drying of cashew apples specifically, sun or solar drying (Falade et al, 2003).…”

Chemical composition and bioactive compounds of cashew (Anacardium occidentale) apple juice and bagasse from Colombian varieties

“…Additionally, polyphenols with antioxidant activity [ 12 ] and tannins have been observed in CA from different varieties worldwide [ 6 ]. However, high tannin content is attributed to a strong astringent flavor, which reduces the value of this biomass [ 13 ]. The chemical composition of CA and the occurrence of these components are related to the tree variety, place of cultivation, and storage conditions.…”