SummaryWe investigated in 30 healthy adults the glycemic index (GI) of five strawberry jams made from various sugar compositions. The jam containing the highest ratio of glucose showed a high GI, while that containing a high ratio of fructose, a jam made from polydextrose, showed a low GI. There was a high correlation ( r ϭ 0.969, p ϭ 0.006) between the GI and the predicted GI calculated from the sugar composition of the jams. Moreover, the influence on postprandial blood glucose response after an intake of only 20 g of jam and one slice of bread with 20 g jam was measured in 8 healthy adults. The blood glucose level after an intake of 20 g of the high GI jam containing the high glucose ratio was higher than that of other jams at 15 min, but there was no significant difference after 30 min. Regardless of whether the GI was low or high, differences in the jams were not observed in the postprandial blood glucose level or the area under the curve after eating either one slice of bread (60 g) or one slice of bread with less than 20 g of jam.

In the present study, the standard addition method with Porapak Q column (PQ) extraction and gas chromatography-mass spectrometry analysis was adapted to quantitatively determine the character impact odorants of 'Toyonoka' strawberries. A significant correlation was confirmed between the contents that determine the character impact odorants in the PQ extract and the levels of standards added to the fruit samples; therefore, standard addition analysis might be a useful and reliable method to analyze already-known odorants in fruits. The concentrations of the character impact odorants, especially 2,5-dimethyl-4-hydroxy-2H-furan-3-one, hexanoic acid, γ-dodecalactone, and the esters, were detected at relatively high levels, which could explain why 'Toyonoka' strawberries have abundant aromas.

Chiyoda, Hoko-wase, Toyonoka, Tioga and Chandler, which were used as fruit material for jam processing, were isolated by cellulose thin-layer chromatography and identified by conventional chromatographic and spectrometric techniques. Then, individual anthocyanins were quantified by high performance liquid chromatography (HPLC) using reversed C-18 column and detection at 520 nm.Six strawberry cultivars contained the same five anthocyanins as follows: cyanidin-3-monoglucoside (Cy-3G), pelargonidin-3-monogalactoside (Pl-3Ga), pelargonidin-3-monoglucoside (Pl-3G), cyanidin and pelargonidin in the elution order of HPLC. Anthocyanin content of cv. Chandler was the most abundant (29.60mg/100g fresh mass) while cv. America was the smallest amount of anthocyanin (6.50mg) in the cultivars investigated.In distribution ratio of individual anthocyanin, Pl-3Ga was 85% or above in all cultivars studied.Cv. America was characterized by relative high percentage of Cy-3Ga (12%) and cv. Chandler by Pl-3G (9%). Whereas, cvs. Chiyoda, Hoko-wase and Toyonoka were characterized by relatively similar amount and ratio of anthocyanin. (Received May 16, 1994)

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