HPLC and GC-MS analyses of organic acids, carbohydrates, amino acids and volatile aromatic compounds in some varieties of rice beer from northeast India

Abstract

Rice beer samples of nine different varieties from four states of northeast India were studied for the content of organic acids, carbohydrates and amino acids by high-performance liquid chromatography. The aromatic compounds were detected by gas chromatography-mass spectrometry method. The analysis evinced a wide variation in content of the major organic acids. Lactic acid was found in high concentration in all of the samples, while the other organic acids were present in variable amounts. Among the carbohydrates, glucose was predominant and some other monosaccharides were also detected. Most of the essential amino acids were found to be present and among them aspartic acid was the most abundant. All of the samples contained volatile or semi-volatile aromatic compounds, with phenylethyl alcohol being the most abundant compound. The overall study revealed that this form of drink has important nutritional values for dietary requirements.

Nuclear Magnetic Resonance and Headspace Solid-Phase Microextraction Gas Chromatography as Complementary Methods for the Analysis of Beer Samples

“…Concentrations were calculated by the comparison of integrals from unique assigned peaks from each component molecule ( Table 2 shows the assignment), knowing the number of protons associated with each component signal (N), the number of mass of maleic acid in solution (10 mg added from a 100 mg/mL stock solution) and the volume of sample (175 µL). Concentrations of major organic compounds are listed in Table 3 and appear to be in reasonable agreement with previously published data [12,13]. Quantitative NMR has been demonstrated previously to be a precise method with variations of less than 1.0% [14,15].…”

“…Several compounds were found to be below the detection limit for the method. Further optimization of the method may be possible to produce lower detection, however, the values determined are in a typical range for beer samples [12,13]. The highest isoamyl acetate values were detected in samples 1 and 9, which were both characterized as Belgian style ales.…”

Sensory evaluation of black pigmented rice (Oryza sativacv. Poireton) wine fortified with probioticLactobacillus acidophilusATCC 4356 andLactobacillus sakeiATCC 15521 using fuzzy logic

“…Despite the evolving trend of using bacteria for ethanol production, yeast is still the primary choice for fermentation (2). The production of wine from several rice varieties has been reported (3,4), however, literature related to the production of wine from black pigmented rice is scanty. Several studies have suggested an association between intake of black pigmented rice and health benefits.…”

Optimisation of fermentation process for production of black rice wine and evaluation of its phenolic and volatile compounds

“…The colour of the black rice wine sample was measured using Hunter Lab Color Quest (Ultrascan Vis, HunterLab, USA) in terms of L * a * b *. The L * a * b *, or CIELab, colour space is an international standard for colour measurements, adopted by the Commission Internationale d'Eclairage in 1976 .…”