Grape brandy production, composition and sensory evaluation

Chemical Components of Noncommercial Alcohol Beverage Samples: A Study With the Viewpoint of Toxic Components in Mashhad, Iran

Background

Iran has one of the lowest alcoholic beverage use rates in comparison with other countries, because it is legally forbidden and because of religious beliefs. Even so, unrecorded and noncommercial alcohol remains a considerable concern, which needs special attention.

Objectives

In the current research, we have studied the general composition of noncommercial alcohol samples to identify potentially toxic components in the context of the city of Mashhad in IR Iran.

Patients and Methods

Using a descriptive study, chemical composition records of alcohol samples obtained from Mashhad and its suburbs (from March 2013 to March 2014) were evaluated in terms of ethanol percentage and methanol percentage using gas chromatography. Likewise, the pH of the alcohol and the location of the sample were also considered. Some substances, such as inorganic elements, were not included because there was no information about these substances in the records.

Results

Of 877 reports of alcohol samples, more than 50% were obtained from Mashhad and the rest were from the suburbs. Of the reports, 57.5% were in the spring and summer, followed by 42.5% in the fall and winter. The mean (min-max) of ethanol percentage was 30.04% (0 - 98.4). In four cases, methanol was detected. The mean (min-max) of methanol percentage was 23% (4 - 95).The majority of the samples had an acidic pH.

Conclusions

The composition of unrecorded samples did not raise major toxicological concern beyond ethanol in alcohol products. However, concentration levels of methanol in some unrecorded alcohol samples made these samples detrimental for human consumption.

Determination of geographical origin of alcoholic beverages using ultraviolet, visible and infrared spectroscopy: A review

The identification of the geographical origin of beverages is one of the most important issues in food chemistry. Spectroscopic methods provide a relative rapid and low cost alternative to traditional chemical composition or sensory analyses. This paper reviews the current state of development of ultraviolet (UV), visible (Vis), near infrared (NIR) and mid infrared (MIR) spectroscopic techniques combined with pattern recognition methods for determining geographical origin of both wines and distilled drinks. UV, Vis, and NIR spectra contain broad band(s) with weak spectral features limiting their discrimination ability. Despite this expected shortcoming, each of the three spectroscopic ranges (NIR, Vis/NIR and UV/Vis/NIR) provides average correct classification higher than 82%. Although average correct classification is similar for NIR and MIR regions, in some instances MIR data processing improves prediction. Advantage of using MIR is that MIR peaks are better defined and more easily assigned than NIR bands. In general, success in a classification depends on both spectral range and pattern recognition methods. The main problem still remains the construction of databanks needed for all of these methods.

Variations in Main Flavor Compounds of Freshly Distilled Brandy during the Second Distillation

The present study investigated the variations in main flavor compounds of a Chinese brandy during the second distillation process using headspace–solid-phase microextraction coupled with gas chromatography-mass spectrometry. A total of 97 volatile compounds involving esters, alcohols, aldehydes, ketones, furans, benzene derivatives and terpenes were quantified, and 28 components were identified as key ingredients. By monitoring the second distillation process, it was found that most ethyl esters (ethyl hexanoate, ethyl octanoate, etc.), alcohols (3-methylbutanol, etc.), terpenes (linalool, etc.), acetaldehyde and ionone all had higher values at the beginning of the distillation, but declined gradually or sharply along with the distillation process. However, two esters (ethyl lactate and diethyl succinate), acids (acetic acid, hexanoic acid), benzene derivatives (2-phenylethanol, etc.) and furan (furfural) showed lower levels when the distillation was just started, and gradually increased, accumulating as a large quantity at the end of the distillation.