Dynamics of the loss and emergence of volatile compounds during the concentration of cashew apple juice (Anacardium occidentale L.) and the impact on juice sensory quality

Author(s)

Telles Biasoto, Aline Camarao ^{[1, 2]} ; Sampaio, Karina de Lemos ^[1] ; Nascimento Marques, Emanuel Jose ^[3] ; Azevedo Pereira da Silva, Maria Aparecida ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Dept Food & Nutr, Campinas, SP - Brazil

^[2] EMBRAPA Trop Semiarid, Brazilian Agr Res Corp, Petrolina, PE - Brazil

^[3] Univ Campinas UNICAMP, Inst Chem, Campinas, SP - Brazil

• Document type: Journal article
• Source: Food Research International; v. 69, p. 224-234, MAR 2015.
• Web of Science Citations: 1

Abstract

Concentrating cashew apple juice alters the beverage aroma and flavor, compromising consumer acceptability of the concentrated beverage. To understand the mechanisms involved in these changes, this research characterized the dynamics of the loss and emergence of volatile compounds during cashew apple juice concentration, reporting their impact on beverage sensory quality. Fresh cashew apple juice (103 degrees Brix) was concentrated in a thermal-siphon type evaporator operating in a closed system. Five samples were taken throughout the concentration process with the following soluble solids contents: 11.8 degrees Brix,14.9 degrees Brix, 20.2 degrees Brix, 29.6 degrees Brix and 42.1 degrees Brix. Trained judges rated the aroma note intensities, described as ``fresh cashew apple{''} and ``cooked{''} as perceived in the fresh and concentrated beverages. The headspace volatiles of the six samples were identified and quantified by GC-MS. The results indicated the esters as the major component in the fresh juice (226.46 mu g kg(-1)) representing 45.0% of the total mass of volatiles, followed by the terpenes (118.98 mu g kg(-1)), acids (45.23 mu g kg(-1)), aldehydes (39.10 mu g kg(-1)), alcohols (18.91 mu g kg(-1)), lactones (19.15 mu g kg(-1)), hydrocarbons (18.02 mu g kg(-1)) and ketones (11.05 mu g kg(-1)). Predictive statistical models (R-2 > 0.956, p <= 0.002) revealed that on reaching 14.9 Brix, the ester concentration declined more than 90%, the terpene content almost 100%, alcohols 85%, aldehydes 80% and hydrocarbons 90%. At 14.9 degrees Brix, the intensity of ``fresh cashew apple{''} aroma still predominated in the juice, but the panelists detected the presence of a weak ``cooked{''} aroma. Concentration of the beverage to 20.2 degrees Brix or above expressively increased the cooked aroma intensity and the concentration of hydrocarbons, alcohols and some aldehydes usually associated with off-flavors such as pentanal and decanal. This raises the possibility that some of these compounds might have been formed during juice processing. Juice with better sensory quality could possibly be obtained by concentrating the beverage to levels below 20.2 degrees Brix, recovering the esters that evaporated off the juice until similar to 15 degrees Brix is reached, and re-adding them to the juice concentrated. (C) 2015 Elsevier Ltd. All rights reserved. (AU)