RESUMO
The effect of maturity level on fruit quality properties, volatile composition and sensory attributes was investigated in two important apricot varieties (Hacihaliloglu and Kabaasi). The soluble solid content was used as the maturity index for the classification of apricots according to their maturity levels as immature (14-20 °Brix), mature (20-24 °Brix) and over-mature (> 24°Brix). Changes in the volatile composition of samples at different maturity levels were characterized using headspace solid phase micro-extraction gas chromatography-mass spectrometry. The results showed that the quality attributes of the Kabaasi were affected to a lesser extent by the maturity level than Hacihaliloglu. From the immature to over-mature, fruit weight, dry matter and pH increased while firmness and titratable acidity decreased (p < 0.05) in both varieties. Volatile composition was affected by both apricot variety and maturation levels. The main volatiles were aldehydes, alcohols, ketones, esters, terpenes and hydrocarbons. Compared to Kabaasi, the concentrations of the volatile compounds were higher in Hacihaliloglu regardless of the maturity levels. Among the samples, Hacihaliloglu at over-mature level received the highest "overall liking" score. The principal component analysis made on the measured quality attributes allowed the discrimination of apricot varieties and their maturity levels.
RESUMO
Seven grades of black tea [high-quality black tea (grades 1-3) and low-quality black tea (grades 4-7)], processed by ÇAYKUR Tea Processing Plant (Rize, Turkey), were compared for their differences in descriptive sensory analysis (DSA), aroma-active compounds (volatile compounds), and taste-active compounds (sugar, organic acid, and free amino acid compositions). Ten flavor attributes such as 'after taste', 'astringency', 'bitter', 'caramel-like', 'floral/sweet', 'green/grassy', 'hay-like', 'malty', 'roasty', and 'seaweed' were identified. Intensities for a number of flavor attributes ('after taste', 'caramel-like', 'malty', and 'seaweed') were not significantly different (p > 0.05) among seven grades of black tea. A total of 57 compounds in seven grades of black tea (14 aldehydes, eight alcohols, eight ketones, two esters, four aromatic hydrocarbons, five aliphatic hydrocarbons, nine terpenes, two pyrazines, one furan, two acids, and two miscellaneous compounds) were tentatively identified. Of these, aldeyhdes comprised more than 50% to the total volatile compounds identified. In general, high-grade quality tea had more volatiles than low-grade quality tea. With respect to taste-active compounds, five sugars, six organic acids, and 18 free amino acids were positively identified in seven grades of black tea, of which fructose, tannic acid, and theanine predominated, respectively. Some variations (p < 0.05), albeit to different extents, were observed among volatile compounds, sugars, organic acids, and free amino acids in seven grades of black tea. The present study suggests that a certain flavor attributes correlate well with taste- and aroma-active compounds. High- and low-quality black teas should not be distinguished solely on the basis of their DSA and taste- and aroma-active compounds. The combination of taste-active compounds together with aroma-active compounds renders combination effects that provide the characteristic flavor of each grade of black tea.
