Nutritional composition of pineapple (Ananas comosus (L.) Merr.)
"Smooth Cayenne", accounting for 90% of processing pineapple, has been the backbone of the global pineapple industry for more than a century. Cultivars of the Cayenne group have a high content of total soluble sugar and acidity. Queen group pineapple, mainly for fresh consumption, contains high sugar and moderate acidity. Both sugar and acidity are low in Spanish group cultivars. "Perola" is one of the most important cultivars of the Pernambuco group, with a higher total soluble sugar (14.6°Brix) and a lower acidity (0.37%). The sugar content of 'Perolera' cultivar was 14.1°Brix and the acidity was 0.76%. Hybrid 'MD-2' is a famous cultivar dominating the world fresh pineapple ni.arket. The average percentage ofTSS in MD-2 is 1-2% higher than "Sn1ooth Cayenne". The acidity is lower than that of"Smooth Cayenne". Total sugar contents in 16 modern pineapple cultivars varied from 81.59 to 124.41.65 mg/g FWThe average value (108.14mg/g FW) was higher than that in traditional cultivars (106.29 mg/g FW). However, the highest sugar content was lower than that in traditional cultivars (137.89 mg/ g FW). The values of total organic acid in modern cultivars changed from 1.80mg/g FW to 6.90mg/g FWThe lowest, highest, and average contents of total organic acid in modern cultivars were lower than those in traditional cultivars. Total dietary fib er content varied from 1.46% to 2.80% FWThe average contents of NDF, ADF, CEL, HC, ADL, TP, WSP, and protopectin in 12 cultivars analyzed were 32.70, 20.65, 16.96, 12.24, 2.98, 3.06, 1.16, and 1.91mg/100 g DW, respectively. Vitamin C, vitamin A, vitamin B3, and vitamin B6 contents in 11 varieties changed between 0.10 and 0.23mg/g, 0.0016-0.0038mg/g, 0.0038-0.024mg/g, and 0.0045-0.067 mg/g respectively. It seems that pineapple is a good source of vitamin A, vitamin C, and vitamin B6. Both total polyphenols and flavonoids could be the main components responsible for the antioxidant capacities in pineapple fruit. Total phenolic contents showed significant variations among different genotypes, ranging from 25.71 to 72.57mg GAE/100g FW Catechin, epicatechin, and sinapinic acid were the predominant phenolic compounds. The TF contents of the pulp extracts had significant differences, which varied from 10.40 to 50.57n1g RE/100g FW "MD-2" and "Tainung4" exhibited higher antioxidant capacities than the other cultivars as determined by DPPH,ABTS, and FRAP methods. Eighty-three volatile compounds were detected in six pineapple cultivars, including 15 esters and 57 alkenes and terpenes. Total concentration of aroma in "Tainungl 7" was the highest (8842.09 μg/kg), while in "Queensland Cayenne" it was the lowest (1408.66μg/kg) . Butanoic acid 2-methyl-methyl ester, butanoic acid, 2-methyl-ethyl ester, hexanoic acid methyl ester, hexanoic acid, ethyl ester, and decanal appeared to be the main odor-active compounds.