Karina de Lemos Sampaio

Aroma volatiles recovered in the water phase of cashew apple (Anacardium occidentale L.) juice during concentration

BACKGROUND There is a considerable loss of volatile compounds during the thermal concentration of cashew apple juice, damaging product quality, and as yet there is little research on the subject. Thus the purpose of this research was to identify the aroma volatiles evaporated off from cashew apple juice and recovered in the water phase during concentration of this beverage in an industrial plant. Water phase volatiles were extracted using dichloromethane, concentrated under a nitrogen flow, separated by gas chromatography (GC) and identified by GC-mass spectrometry. In order to determine the contribution of each volatile to the cashew aroma, five trained judges evaluated the GC effluents using the Osme GC-olfactometry technique. RESULTS 71 volatiles were identified; of these, 47 were odour active. Alcohols were preferentially recovered in the cashew water phase, notably heptanol, trans-3-hexen-1-ol and 3-methyl-1-butanol, representing 42% of the total chromatogram area and imparting green grass and fruity aroma notes to the water phase. Esters represented 21% of the total chromatogram area, especially ethyl 2-hydroxyhexanoate, ethyl trans-2-butenoate and ethyl 2-methylbutanoate, and were responsible for the fruity/cashew-like aroma of the water phase. On the other hand, 3-methylbutanoic and 2-methylbutanoic acids were the volatiles that presented the greatest odour impact in the GC effluents of the water phase. CONCLUSION Overall, the results of the present study strongly indicated that further concentration of the esters recovered in the water phase, either by partial distillation or by alternative technologies such as pervaporation, could generate a higher-quality natural cashew apple essence.

Association between Taste Sensitivity and Self-Reported and Objective Measures of Salt Intake among Hypertensive and Normotensive Individuals

This study investigated the gustatory threshold for salt and its relationship with dietary salt intake among hypertensive (n = 54) and normotensive (n = 54) subjects. Salt intake was evaluated through 24-hour urinary sodium excretion and self-reported measures (discretionary salt, Sodium- Food Frequence Questionnaire (Na-FFQ), and 24-hour recall). Detection and recognition thresholds were higher among hypertensive subjects, as well as the total sodium intake. Detection and recognition thresholds were positively related to discretionary salt and total intake of the group as whole. Hypertensive and normotensive subjects presented positive correlations between taste sensitivity and the different measures of salt intake. To conclude, a positive correlation exists between taste threshold and salt intake and both seem to be higher among hypertensive subjects. The combined use of methods of self-report and assessment of taste thresholds can be useful in health promotion and rehabilitation programs, by screening subjects at higher risk of elevated salt intake and the critical dietary behaviors to be targeted as well to evaluate the result of targeted interventions.

Revisão: metodologias para análise da sensibilidade gustativa ao sal

The assessment of gustatory sensibility to salt is applied both in healthcare and in sensory analysis in the area of Food Science and Technology, to evaluate the taste and identify several origins of ageusia and hypogeusia, and notably to identify individuals at risk or who present a high salt intake. The adoption of an accurate and reproducible method to evaluate the taste threshold for salt would contribute to its widespread use. This integrative review aims to describe the methodologies employed to assess the detection threshold and recognition of sodium chloride. The databases used were CINAHAL, LILACS and MEDLINE and the keywords: taste threshold, sodium chloride and salt. Twenty-seven articles from 1985 to 2009 were identified and 29 tests were used to analyze the threshold. The majority of the articles used stimulation of the whole mouth (75.9%), followed by topical application on the tongue (24.1%), applying the solution to parts of the tongue (10.3%), electrogustometry (6.4%), impregnated disc (3.4%) and vacuum application (3.4%). There was considerable variability in the methodological procedures and important information was missing in some of them. The articles did not present the basis for the sample size, and the selection criteria for the panellists were extremely varied. Thus reproducibility of the studies and comparison of the articles was difficult. Benchmarking between different methods of evaluation of the taste threshold for salt with respect to their reproducibility could provide benefit in the choice of the most appropriate method to be employed in research and clinical practice.

Comparison of techniques for the isolation of volatiles from cashew apple juice

BACKGROUND The aim of this study was to compare the performance of the following techniques on the isolation of volatiles of importance for the aroma/flavor of fresh cashew apple juice: dynamic headspace analysis using PorapakQ(®) as trap, solvent extraction with and without further concentration of the isolate, and solid-phase microextraction (fiber DVB/CAR/PDMS). RESULTS A total of 181 compounds were identified, from which 44 were esters, 20 terpenes, 19 alcohols, 17 hydrocarbons, 15 ketones, 14 aldehydes, among others. Sensory evaluation of the gas chromatography effluents revealed esters (n = 24) and terpenes (n = 10) as the most important aroma compounds. CONCLUSION The four techniques were efficient in isolating esters, a chemical class of high impact in the cashew aroma/flavor. However, the dynamic headspace methodology produced an isolate in which the analytes were in greater concentration, which facilitates their identification (gas chromatography-mass spectrometry) and sensory evaluation in the chromatographic effluents. Solvent extraction (dichloromethane) without further concentration of the isolate was the most efficient methodology for the isolation of terpenes. Because these two techniques also isolated in greater concentration the volatiles from other chemical classes important to the cashew aroma, such as aldehydes and alcohols, they were considered the most advantageous for the study of cashew aroma/flavor.

Reliability of a Simple Method for Determining Salt Taste Detection and Recognition Thresholds

The aim of this study was to assess the reliability of a rapid analytical method to determine salt taste detection and recognition thresholds based on the ASTM E679 method. Reliability was evaluated according to criterion of temporal stability with a 1-week interval test-retest, with 29 participants. Thresholds were assessed by using the 3-AFC technique with 15 ascending concentrations of salt solution (1-292 mM, 1.5-fold steps) and estimated by 2 approaches: individual (geometric means) and group (graphical) thresholds. The proportion of agreement between the test and retest results was estimated using intraclass coefficient correlations. The detection and recognition thresholds calculated by the geometric mean were 2.8 and 18.6mM at session 1 and 2.3 and 14.5mM at session 2 and according to the graphical approach, 2.7 and 18.6mM at session 1 and 1.7 and 16.3mM at session 2. The proportion of agreement between test and retest for the detection and recognition thresholds was 0.430 (95% CI: 0.080-0.680) and 0.660 (95% CI: 0.400-0.830). This fast and simple method to assess salt taste detection and recognition thresholds demonstrated satisfactory evidence of reliability and it could be useful for large population studies.

Acceptability of an Alimentary Supplement of Whey-Protein Concentrate and TGF-β in Patients with Crohn’s Disease

The objective of this study was to evaluate the acceptability of an alimentary supplement of bovine whey-protein concentrate (WPC) and TGF-β, unavailable commercially, by patients with Crohns disease (CD) and determine the chemical composition, solubility, and total amino acids content. The supplement was diluted in water, and an acceptance test was done to evaluate the aroma, flavour, and viscosity of the product using facial hedonic scale (nine-point scale), applied on 54 CD patients. The supplement composition indicated 73.3% protein, 10.5% fat, 2.2% ash, 6.3% water, and 7.7% carbohydrate. The supplement is presented as a good protein source and high content of essential amino acids. The average acceptance for all the attributes was between 5.0 and 6.0, and the flavour was mainly associated with soybean/grain, sour milk, and sweet/vanilla flavour. The results indicated that the supplement provided important nutritional properties for CD patients; however, for a large number of individuals to be encouraged to perform supplementation, it is essential to improve the sensory quality of the product. In order to do so, additional research is necessary to prevent the formation of volatiles which cause off-flavours or to mask undesirable aromas/flavours found in it.