Rapid concurrent analysis of fruit sugars and acids by gas‐liquid chromatography

Abstract

A rapid and simple procedure for the separation, identification and quantitative analysis of common fruit sugars and non-volatile organic acids has been developed. Acids were precipitated as their lead salts from fruit ethanolic extracts and the sugars in the remaining supernatant and washings were partitioned into aqueous methanol. These preparations with internal standards were dried and converted to their trimethylsilyl derivatives for analysis by gas-liquid chromatography. In model studies, conditions which permitted full recovery of sugars from the lead salts of acids, while minimising the loss of acids, were investigated. For fruit acids reported present in measurable amounts (10 mg/100 g of fruit), replicate analysis of aliquots from the same extract was within k5 % for malonic, phosphoric, succinic, malic, citric, ascorbic and galacturonic acids and within i 1 2 % for quinic acid. The use of the method, its advantages and limitations, in determining individual and total sugars and acids is illustrated on some New Zealand grown fruit (New Zealand grapefruit, mountain pawpaw, tangelo, apricot). Total sugars and total acids determined by this procedure gave comparable results with those obtained by using standard A.O.A.C. procedures.

Feijoa fruit: Growth and chemical composition during development

“…The concentration of individual sugars and organic acids in freeze-dried fruit samples was measured by GLC (Heatherbell 1974). Silylated derivatives of sugars and organic acids were injected onto a 2 m x 3.16 mm nickel column packed with 5070 0 VIOl ® on Chromosorb® WHP in a Varian Model 2700 gas chromatogram.…”

Boysenberries: Preliminary studies on effect of ripening on composition

“…The solution was applied to a 5 ml QAE-Sephadex® column (Pharmacia Fine Chemicals AB) which was prepared and eluted according to Redgwell (1980). The method used for the determination of sugars and non-volatile organic acids was modified from Heatherbell (1974).…”

HPLC Analysis of Organic Acids and Sugars in Tomato Juice

“…Several chromatographic approaches have been published on organic acid determinations, including partition chromatography on silica gel columns with gradient elution (Carangal et al, 1954) and gas chromatographic (GC) determinations of the trimethylsilyl derivatives (Heatherball, 1974). Anion exchange column was used successfully to separate organic acid mixtures (Palmer and List, 1973;Hyakutaki and Hanai, 1975).…”

“…Palmer and Brandes (1974) detected glucose, fructose and sucrose in fruits by liquid cation exchange chromatography. Heatherball (1974) reported the separation, identification and quantitation of common fruit sugars by GC as their trimethylsilyl derivatives with a low recovery of the total sugars present. Hyakutaki and Hanai (1975) used high speed liquid chromatography with a 2 meter stainless steel CORASIL AX column for the separation of sugars.…”