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

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 (10.3°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°Brix, 14.9°Brix, 20.2°Brix, 29.6°Brix and 42.1°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 μg kg −1 ) representing 45.0% of the total mass of volatiles, followed by the terpenes (118.98 μg kg −1 ), acids (45.23 μg kg −1 ), aldehydes (39.10 μg kg −1 ), alcohols (18.91 μg kg −1 ), lactones (19.15 μg kg −1 ), hydrocarbons (18.02 μg kg −1 ) and ketones (11.05 μg kg −1 ). Predictive statistical models (R 2 N 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°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°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°Brix, recovering the esters that evaporated off the juice until~15°Brix is reached, and re-adding them to the juice concentrated.

Adsorption Mechanism of Patulin from Apple Juice by Inactivated Lactic Acid Bacteria Isolated from Kefir Grains

“…On the other hand, sensor W1W, highly developed in AJD, reacted on many terpenes, organic sulfides, and inorganic sulfide (H2S), which were poor in ADJ. These were the same findings as Biasto et al [ 60 ], who concluded that high °Brix content apple juice was reduced in terpenes. W1C, W1S, W2S, W6S, and W5S were greatly developed in AJD.…”

Comparative analysis of fresh and processed mango (Mangifera indica L, cv. “Maria”) pulps: influence of processing on the volatiles, bioactive compounds and antioxidant activity

“…Among the samples analyzed, the ones that underwent thermal treatment presented lower amounts of compounds, being this factor due to the process of pasteurization, that brought about a decrease in the number of compounds resulting from the heating effect and the consequent volatilization of some highly volatile compounds. The reduction in the number of identified terpenes and even in some cases the increase in specific terpenes, such as β-pinene, can be explained by the fact that the thermal processing, under acidic conditions, can cause the conversion of the terpenes to other terpenes, however, many of these compounds cannot be detected in the chromatographic run because of their low volatility, as reported by Biasoto et al (2015). In summary, an explanation for the reduction or increase of the terpenes in the thermally treated mango pulp would be due to the sensitivity of these compounds, which may degrade to other compounds during thermal processing, depending on their polarity.…”

Physicochemical properties of and volatile compounds in riboflavin fortified cloudy apple juice; study of its effect on job fatigue among Egyptian construction workers

“…(2007) during the processing of apple juice concentrate. On the other hand, an increase in ketones and alcohols was observed in processed apple juice according to multiple studies ( Schmutzer et al., 2014 ; Biasoto et al., 2015 ). Su and Wiley (2006) .…”

“…In addition, there is a loss of about 33.3-59.9% in ethyl 2-methyl butyrate and 55.3-75.4% in hexanal as reported by Komthong et al (2007) during the processing of apple juice concentrate. On the other hand, an increase in ketones and alcohols was observed in processed apple juice according to multiple studies (Schmutzer et al, 2014;Biasoto et al, 2015). Su and Wiley (2006).…”