Comparison of Enzymic, Gas-Liquid Chromatographic, and High Performance Liquid Chromatographic Methods for Determining Sugars and Organic Acids in Strawberries at Three Stages of Maturity

Abstract Free sugars and major nonvolatile organic acids present in strawberries at 3 degrees of ripeness were determined by 3 analytical methods: enzymic, gasliquid chromatographic, and high performance liquid chromatographic. Results showed that variability in sugar composition due to both degree of ripeness and method of analysis was greater for sucrose than for glucose and fructose. Sucrose was almost completely hydrolyzed in the overripe fruit. Acid results showed that there was little variation in citric acid levels due to ripeness or method of analysis; malic acid, however, decreased greatly in overripe fruit. Malic acid also showed high variability due to method of analysis. The glucose:fructose ratios for the underripe, ripe, and overripe fruit were 0.86,0.92, and 0.60, respectively. The citric:malic ratios were 1.58, 2.39, and 14.86 for the underripe, ripe, and overripe stages, respectively.

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Degradation studies of organic acids in commercially packed fruit juices: A reverse phase high performance liquid chromatographic approach

International Journal of Food Engineering ◽

10.1515/1556-3758.1821 ◽

2012 ◽

Vol 8 (4) ◽

Cited By ~ 1

Author(s):

Ruchika Raghav ◽

Nisha Yadav ◽

Gunjan Tyagi ◽

Deepak K. Jangir ◽

Ranjana Mehrotra ◽

...

Keyword(s):

Citric Acid ◽

Organic Acids ◽

High Performance ◽

High Performance Liquid Chromatographic ◽

Fruit Juices ◽

Reverse Phase ◽

Liquid Chromatographic Method ◽

Orange Fruit ◽

Liquid Chromatographic ◽

Ammonium Dihydrogen Orthophosphate

Abstract Organic acids are important constituents of fruit juices. They render tartness, flavour and specific taste to fruit juices. Shelf life and stability of fruit juices are important factors, which determine their nutritional quality and freshness. In this view, the effect of storage on the concentration of organic acids in commercially packed fruit juices is studied by reverse phase high performance liquid chromatography (RP-HPLC). Ten packed fruit juices from two different brands are stored at 30°C for 24, 48 and 72 hours. A reverse phase high performance liquid chromatographic method is used to determine the concentration of oxalic, tartaric, malic, ascorbic and citric acid in the fruit juices during storage. The chromatographic analysis of organic acids is carried out using mobile phase 0.5% (w/v) ammonium dihydrogen orthophosphate buffer (pH 2.8) on C18 column with UV-Vis detector. The results show that the concentration of organic acids generally decreases in juices under study with the increase in storage time. All the fruit juices belonging to tropicana brand underwent less organic acid degradation in comparison to juices of real brand. Orange fruit juice is found to be least stable among the juices under study, after the span of 72 hours. Amongst all the organic acids under investigation minimum stability is shown by ascorbic acid followed by malic and citric acid.

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