Determination of organic acids evolution during apple cider fermentation using an improved HPLC analysis method

Abstract

An eYcient method for analyzing ten organic acids in food, namely citric, pyruvic, malic, lactic, succinic, formic, acetic, adipic, propionic and butyric acids, using HPLC was developed. Boric acid was added into the mobile phase to separate lactic and succinic acids, and a post-column buVer solution [5 mmol/L p-toluensulfonic acid (p-TSA) + 20 mmol/L bis (2-hydroxyethyl) iminotris (hydroxymethyl) methane (bis-tris) + 100 mol/L sodium ethylenediaminetetraacetic (EDTA-2Na)] was used to improve the sensitivity of detection. The average spiked recoveries for the ten organic acids ranged from 82.9 to 127.9% with relative standard deviations of 1.44-4.71%. The linear ranges of determination were from 15 to 1,000 mg/L with correlation coeYcients of 0.9995-0.9999. The metabolism of organic acids in cider, and the eVect of nutrients including diammonium phosphate (DAP), thiamine, biotin, niacinamide and pantothenic acid on their metabolism, were studied using this method of analysis. We found that before cider brewing, additions of 200 mg/L DAP and 0.3 mg/L thiamine to apple juice concentrate results in a high quality cider.

Determination of benzoate, sorbate, citrate and orthophosphate ions in beverage samples using two-dimensional isotachophoretic method

“…These results were similar or better than those reported for chromatographic [2,4,7,8,16,17] and electro phoretic analysis [22,24,26].…”

“…In comparison, DL obtained for citric acid determination by HPLC method was 8.76 mg/L [7] and by ion exchange chro matography was 4.7 mg/L [18]. In the case of UV Vis detection, the sensitivity for both calibration curves was similar and calculated DL and QL values were from 0.85 to 3.1 mg/L and from 2.8 to 10 mg/L.…”

“…Only for citric acid the obtained recov ery was higher than 100%. For comparison, the recov eries obtained by IC method for this ion were as fol lows: 99.7-105.9% [16], whereas by CZE, HPLC and GC methods were 99.4% [23], 94.4-100% [7] and about 98% [12], respectively. The CE method, which was the combination of the large volume sample stack ing and the dynamic pH junction technique, was applied to the determination of benzoic and sorbic acid and reported recoveries were 96.4 and 93.4%, respectively [25].…”

“…Most of the reported methods are based on chromato graphic methods such as high performance liquid chromatography (HPLC) [2,[4][5][6][7], gas chromatogra phy (GC) [8][9][10][11][12], micellar electrokinetic chromatog raphy [13][14][15] and ion chromatography (IC) [16][17][18]. Nowadays, electrophoretic methods have become an attractive analytical technique for preservatives due to its high separation efficiency, low sample consumption and short analysis time [3,[19][20][21][22][23].…”

Characterisation of single-variety still ciders produced with dessert apples in the Italian Alps

“…The overall microbiological management of fermentation was satisfactory, as proved by the low volatile acidity values, with the exception of one sample (red-fermented Golden Lasa), and by the low concentration of lactic acid (≤0.20 mg/L) in all white-processed ciders, while red processing increased lactic acid production. Citric acid, which increases during fermentation (45,46), was higher in white-processed ciders, as is common in white wine (47) compared with unsupplemented red wine, in which citric acid is usually metabolised by lactic bacteria (48).…”