Effects of tannin, ascorbic acid, and total phenolic contents of cashew (Anacardium occidentale L.) apples blanched with saline solution

Abstract

Cashew apple (Anacardium occidentale) is considered as a by-product of the cashew processing industry. Efficient utilization of this material source contributes to valorization of cashew and reduces the burden of agricultural waste placed on the environment. This study investigated the effects of various blanching conditions on the total tannins, the ascorbic content and the phenolic contents of cashew apples. The three parameters including blanching temperature, blanching duration and salt concentration of the blanching solution were considered. It was found that optimal blanching conditions (heating at 70°C, NaCl concentration at 1% within 2 mins) resulted in cashew apples with vitamin C content and tannin retention rate of about 78.125% and 45% compared to those of the fresh samples, respectively. The cashew apple texture seemed to be insensitive to the heating process, however, the colors (mainly red gamuts of carotenoids) were lost during blanching.

Study of jelly drying cashew apples (Anacardium occidentale L.) processing

“…The blanching process was carried out under previously reported optimal conditions including 1% saline solution at 70°C for 3 min (Dao et al., 2021). The material size was allowed to vary from 4 to 10 mm.…”

“…However, those processes have been shown to be unable to completely eliminate the residual tannin in the fruit juice, leaving a moderate taste of acrid and bitterness and negatively affecting the consumer acceptance of the resulting product. In a recent study, we successfully implemented the blanching process with saline solution to significantly reduce the tannin in the cashew apple while still maintaining adequate vitamin C content in the product (Dao et al., 2021). In the current study, a manufacture process in which cashew apples are processed into jelly dried cashew apple (JDC) was proposed.…”

“…In the current study, a manufacture process in which cashew apples are processed into jelly dried cashew apple (JDC) was proposed. First, we investigated the blanching process with regard to changes in ascorbic acid content (TAA), total phenolic content (TPC), and total tannin content (TTC) during blanching (Dao et al., 2021). The blanching process aims to inactivate the browning enzyme, increase moisture loss, and reduce the tannin content to an acceptable organoleptic level.…”

Blanching effect on physicochemical and functional properties of flours processed from peeled and unpeeled white‐fleshed sweet potato Algerian cultivar

“…In Dako et al study (2016), tannins were accumulated in the outer skin layer of yellow sweet potato variety and t were removed by peeling with the outer skin layer of the root. Blanching contributed also to the tannin content lowering probably because they are thermolabile antioxidants that are highly soluble in water (Dao et al, 2021). In fact, the decrease reached 48% and 63% in unpeeled and peeled SP based-flours, respectively.…”

Effects of ultrasound support and carboxymethyl cellulose on the physicochemical properties, sensory evaluation and total microbiology of cloudy juice from soursop (Annona muricata l.)

“…Then, 500µl of Folin-Ciocalteu reagent were mixed with 100µl diluted sample (ratio 1:4), 400µl of Na2CO3 7.5% (w/v). The method for determining TPC was adjusted by Silva et al [23]. Absorbance at 760nm was measured after one h, using a spectrophotometer.…”