The Beer Phenolic Profile Change During «Dry» Hopping in the Post-fermentation Stage Conditions

Статья посвящена вопросу изменения фенольного профиля пива в условиях «холодного» охмеления во время дображивания пива. Оценено влияние метаболизма дрожжевых клеток и типа хмеля во время дображивания на изменение общего количества полифенолов, изоксантогумола, изогумулона, кверцетина и рутина. Показано, что применение низовой расы дрожжей Rh и горького типа хмеля Mагнум позволяет добиться высокого (до 123,0 мг/дм3) содержания полифенолов в пиве к 1 сут «холодного» охмеления в отличие от тонко-ароматного хмеля Tетнангера, применение которого дает максимум количества полифенолов к 14 сут процесса. Применение верховой расы дрожжей Nottinghem приводит к замедлению увеличения концентрации полифенолов в среде, поскольку только к 7-14 сут вне зависимости от типа хмеля происходит их накопление. Показана зависимость в течение первых 14 сут изменения количества изоксантогумола от расы дрожжей и типа хмеля, а в последующем - только от типа хмеля. Авторами получены результаты, свидетельствующие о том, что кверцетин не вовлекается низовыми дрожжами в метаболический цикл, в отличие от верховых. Изменение концентрации рутина в пиве не зависит от расы дрожжей, и определяется своим содержанием в хмеле определенного типа. В работе показана взаимосвязь между процессами изменения содержания изогумулона и изоксантогумола при «холодном» охмелении в зависимости от ряда факторов. Проведение органолептического анализа позволило соотнести балловую оценку дескрипторов пива с основными показателями фенольного профиля. The article is devoted to the issue of beer phenolic profile changing in the conditions of «dry» hopping during the after-fermentation of beer. The influence of the yeast cells metabolism and the hop type during fermentation on the change in the polyphenol, isoxanthohumol, isogumulone, quercetin and rutin total amount, was evaluated. It has been shown that the Rh lager yeast race use and the Magnum bitter hop type makes it possible to achieve a high (up to 123.0 mg/dm3) polyphenol content in beer by 1 day of «dry» hopping, in contrast to the finely aromatic Tettnanger hops, the use of which gives the maximum polyphenol amount by 14 days of the process. The Nottinghem ale yeast race use leads to a slowdown in the polyphenol concentration increase in the medium, since their accumulation occurs only by 7-14 days, regardless of the hop type. The dependence during the first 14 days of the change in the isoxanthohumol amount on the yeast race and the hop type, and subsequently - only on the hop type was shown. The authors obtained results indicating that quercetin is not involved in the metabolic cycle by lager yeast, in contrast to ale yeast. The change in the rutin concentration in beer does not depend on the yeast race and is determined by its content in a certain type of hop. The paper shows the relationship between the processes of changing the isogumulone and isoxanthohumol content during «dry» hopping, depending on several factors. Organoleptic analysis made it possible to correlate the beer descriptors scoring with the phenolic profile main indicators.

Occurrence and Levels of Biogenic Amines in Beers Produced by Different Methods

The concentration of biogenic amines (BAs) in beer depends, among other factors, on the activity of microorganisms, in particular lactic acid bacteria. In this work an analytical method based on derivatization with tosyl chloride and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to determine 17 BAs in samples of commercially available beers, and to monitor the changes in concentration of several BAs throughout the fermentation process. In some of the analysed samples the concentration of BAs exceeded the safety threshold for consumers. During the fermentation stage of home-brewing of ale the concentration of spermine in the wort increased until the end of the stormy fermentation, to then drop below the initial concentration at the end of fermentation, and below the LOQ after refermentation. The results of the study indicate that monitoring the total content of BAs is required due to the potential risk to human health.

Development of Lactic acid Microorganisms during Fermentation of Substrate with an Increased Concentration of Carbohydrates

Introduction. Creating favorable conditions for the development of lactic acid microorganisms is one of the main factors in obtaining high-quality fermented products. The cycle of their life directly depends on the amount and composition of carbohydrates in plant tissue. Since a significant part of carbohydrates is consumed at the initial stage of fermentation process, additional fortification is needed. The research objective was to study the development rate of lactic acid microorganisms during the fermentation of plant substrate with a modified carbohydrate composition. Study objects and methods. The research featured model medium based on white cabbage of the Parus variety. The medium was fermented with different strains of lactic acid microorganisms: at the first stage of fermentation – Leuconostoc mesenteroides, at the second stage – Lactobacillus casei VKM 536, Lactobacillus plantarum VKM B-578, Lactobacillus brevis VKM B-1309, and their paired consortia. The initial plant material was subjected to grinding and removal of native microflora for the development of target lactic acid microorganisms, then inoculated with L. mesenteroides. The target lactic acid microorganisms were introduced after the first stage of fermentation with simultaneous adjustment of the carbohydrate composition. Results and discussion. The technology included modes of controlled two-stage microbial transformation of plant raw materials using modification of the carbohydrate composition of the substrate. A number of experiments made it possible to select the optimal composition of the consortium and establish the optimal fermentation time at the main stage of microbial processing. When the plant substrate was fermented by the consortium of L. casei + L. plantarum with an increased carbohydrate component, the decrease in the concentration was quite small: after 5–30 days, the decrease in the concentration of microorganisms did not exceed one order of magnitude, which was insignificant at an initial concentration of eight orders of magnitude. In other consortia, the decrease in the concentration of microorganisms was more pronounced. Conclusion. The fortification of the vegetable substrate with carbohydrates made it possible to maintain the concentration of lactic acid microorganisms at a level comparable to the concentration at the time of inoculation. The concentrations of microorganisms varied slightly in both monocultures and their paired consortia during the entire main fermentation stage of the model medium with a modified carbohydrate component. By the end of the main fermentation stage, the concentration of microorganisms did not fall below 107 CFU/g. Therefore, the resulting system “microflora – substrate” proved to have probiotic properties. The study can be used to develop new technological modes of controlled step-by-step fermentation of plant raw materials in order to improve the quality indicators of the final product.

The use of dry hopping technique in brewing

Currently, the application of the dry hopping process is a new technology. This method of introducing hops allows you to preserve unstable aromatic oils. The dry hopping process means the addition of hop products at the fermentation stage of the fermentation chine or kegs after the fermentation process is completed. The dry hopping technology does not give the beer a bitter taste, but as a result of its use, it allows you to preserve volatile unstable aromatic oils that evaporate during cooking: monoterpenes-myrcene , diterpenes-dimircene, sexwiterpenes-β-corpofyllene, etc. Beer prepared using this technology is characterized by a rich aroma of hops, which is not present in traditional brewing technology. Based on the production tasting quality assessment, sensory profiles and physico-chemical parameters of drinks with different concentrations of Goldings hops were determined, in particular, the content of the extract, pH, the content of bitter substances, color, diacetyl content, alcohol content, the degree of fermentation, and according to the results of the profilogram analysis, the optimal dose of hops administration was 29 g/dal.

Optimalisasi Kadar Asam Asetat Ananas Comosus l dengan Penambahan Induk Cuka

Ananas comosus L. (Pineapple) is one of the superior fruit commodities in Indonesia. The amount of production in 2016 pineapples placed fourth after bananas, oranges and mangoes which amounted to 1.4 million tons/year. Pineapple production for East Kalimantan, Balikpapan city has an area of 8,572 hectares of pineapple with a production of 7,206 tons of pineapple. Pineapple skin contains 17.53% carbohydrates and 13.65% sugar. This led researchers to develop the manufacture of acetic acid from the skin waste of Ananas comosus L. The research method consists of materials used namely, pineapple skin, water, granulated sugar, yeast, vinegar, ammonium sulfate, oxalic acid, sodium hydroxide, pp indicators and aquades obtained from STTI Bontang laboratory. The working procedure of this study consists of 3 stages of the method: the first fermentation stage with the addition of Saccharomyces cerevisiae, the second fermentation stage with variations in the addition of the parent vinegar and the calculation of acetic acid levels with time intervals of 2 days /sample (days 16, 18, 20, 22 and 24). The third stage is carried out by alkaline method. Optimum results from research with the main variation of vinegar and fermentation time were obtained on the 20th day with the addition of a 2.3 mL vinegar master obtained a acetic acid content of 6.24 g/mL. Further researchers are expected to develop better analytical methods to make the concentration of acetic acid obtained more optimal.

The Possibility of Obtaining Highly Fermented Rye Malt with the Use of Organic Processing

Производство солода - это актуальное направление развития пищевой отрасли. От качества солода напрямую зависит качество готового напитка пивобезалкогольной отрасли. В технологии кваса используют ржаной солод двух видов - неферментированный и ферментированный, первый солод как источник ферментов, второй - вкусоароматических соединений. С целью улучшения технологических характеристик солода применяют различные способы воздействия на зерновое сырье на разных технологических стадиях. Авторы предлагают способ получения ржаного солода с применением стимулирующей обработки ржи на стадии замачивания. С этой целью по окончании замачивания, последние 6 ч выдержки зерна под слоем воды, в замочную воду вносят комплекс органических кислот из цикла Кребса в концентрации 10-9 моль/дм3 и выдерживают с ним 6 ч. Данная обработка позволяет усилить накопление ферментного потенциала зерна, и в первые 6 ч выдержки уровень амилолитической, протеолитической и цитолитической активностей превышает уровень аналогичных ферментов в необработанном зерне на 4,7; 9,8 и 3,5%, соответственно. Следующая стадия проращивания приводит к интенсивному накоплению ферментативной активности в ржаном солоде. Последующая сушка, а в случае ферментированного солода дополнительная стадия ферментации, провоцирующие естественное падение уровня гидролитических ферментов, приводят к накоплению ферментативной активности, ед./г: 215,0±1,0 (амилолитической), 57,2±0,1 (протеолитической), 315,0±1,0 (цитолитической) для неферментированного солода и 182,0±1,0 (амилолитической), 51,2±0,1 (протеолитической) и 286,0±1,0 (цитолитической) для ферментированного, что на 11-25% выше тех же показателей ржаного солода, полученного традиционным способом. Полученный ржаной солод (неферментированный и ферментированный) рекомендуется использовать в технологии кваса. Malt production is an actual direction of development of the food industry. The quality of the finished beverage of the beer and non-alcoholic industry directly depends on the quality of the malt. The kvass technology uses two types of rye malt - unfermented and fermented, the first malt as a source of enzymes, the second - flavoring compounds. In order to improve the technological characteristics of malt, various methods of influencing grain raw materials are used at different technological stages. We propose a method for producing rye malt with the use of stimulating rye processing at the soaking stage. For this purpose, at the end of soaking, the last six hours of grain aging under a layer of water, a complex of organic acids from the Krebs cycle is introduced into the water in a concentration of 10-9 mol/dm3 and aged with it for six hours. This treatment increases the accumulation of the enzyme potential of the grain, and in the first six hours of exposure, the level of amylolytic, proteolytic and cytolytic activity exceeds the level of similar enzymes in the untreated grain by 4.7; 9.8 and 3.5%, respectively. The next stage of germination leads to an intensive accumulation of enzymatic activity in rye malt. Subsequent drying, and in the case of fermented malt, an additional fermentation stage, provoking a natural drop in the level of hydrolytic enzymes, leads to the accumulation of enzymatic activity, units/g: 215.0±1.0 (amylolytic), 57.2±0.1 (proteolytic), 315.0±1.0 (cytolytic) for unfermented malt and 182.0±1.0 (amylolytic), 51.2±0.1 (proteolytic) and 286.0±1.0 (cytolytic) for fermented, which is 11-25% higher than the same indicators of rye malt obtained in the traditional way. The resulting rye malt (unfermented and fermented) is recommended for use in kvass technology.

Microbial Community Succession and Metabolite Changes During Fermentation of BS Sufu, the Fermented Black Soybean Curd by Rhizopus microsporus, Rhizopus oryzae, and Actinomucor elegans

BS Sufu is a fermented food that is made by mixed black soybeans and soybeans. Microbial communities and metabolites play an important role for the final product. We characterized microbial diversity of BS Sufu during fermentation by high-throughput DNA sequencing. Meanwhile, volatile compounds were investigated by solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry (GC-MS). The results showed that bacterial diversity was higher than that of fungi in BS Sufu. We found the existence of bacterial and fungal core communities, including Enterococcus, Enterobacter, Rhizopus, and Monascus. Network analysis indicated that bacterial and fungal communities maintain positive and negative interactions, which are important to shape the resident microbial communities in Sufu. In addition, 17 free amino acids (FAAs) were detected at the post-fermentation stage, and umami amino acid mainly contributed to taste of BS Sufu. Furtherly, a total of 79 volatile constituents in BS Sufu, including nine alcohols, 31 esters, and four aldehydes, form synergistically the unique odor of Sufu. Additionally, the correlations between microbiota and metabolites were analyzed. Our results suggested that these microbial taxa and metabolites contribute to the taste and flavor of BS Sufu. This study provided information for analysis of BS Sufu at different fermentation periods in terms of the microbial diversity and metabolites, and this information was important to understand the properties of mixed soybeans Sufu.

Utilization of Bioetanol Fermentation Waste Pineapple and Coconut Water as Disinfectants With Bacteria Saccharomyces Cerevisiae

Research analysis of sugar content and the effect of ethanol content on bioethanol from old coconut water and pineapple peel with the help of Saccharomyces Cerevisease bacteria. The condition of the spread of the Corona Virus or COVID-19 in Indonesia, thus making bioethanol produced from fermenting pineapple peel waste and old coconut water for disinfectant products to spray around homes and public places to reduce bacteria and viruses. The production of bioethanol is carried out by pre-treating coconut water and pineapple peel, the fermentation stage with Saccharomyces cerevisiae yeast and the distillation stage. The result of the highest bioethanol content was 32% with a mass of 5 g yeast with a time of 24 hours. The highest calorific value at 72 hours was 211.95 kcal/kg. The result of the highest specific gravity at 24 hours and the mass of yeast 4 g is 0.98 g/ml. Based on the bioethanol quality requirements, the bioethanol produced is not in accordance with the bioethanol quality requirements, this is due to the absence of nutrient decomposing bacteria so that it is less than optimal in converting glucose into bioethanol.

Antioxidant and Anti-Inflammatory Properties of Probiotic Candidate Strains Isolated during Fermentation of Agave (Agave angustifolia Haw)

Agave species are a source of diverse products for human use, such as food, fiber, and beverages, which include mezcal, a distilled beverage produced by spontaneous fermentation. Agave is an excellent source of high amounts of sugars, minerals, and phenolic compounds, which favor the growth of lactic acid bacteria (LAB) and yeast communities. In this work, 20 promising LAB strains with probiotic characteristics were isolated from the agave fermentation stage in mezcal production. The strains belonged to Lactobacillus plantarum (15), Lactobacillus rhamnosus (2), Enterococcus faecium (2), and Lactococcus lactis (1). These isolates were characterized for their resistance under gastrointestinal conditions, such as lysozyme, acid pH, and bile salts. In addition, the adherence of these LABs to human intestinal epithelial cells (Caco-2 and HT-29 cells) was tested in vitro and their antioxidant and immunomodulatory profile was determined using cellular models. Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 and LM19 strains were selected for their antioxidant properties, and their capacities in an oxidative stress model in intestinal epithelial cells IECs (Caco-2 and HT-29 cells) in the presence of hydrogen peroxide were evaluated. Interestingly, Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 and LM19 strains showed anti-inflammatory properties in TNF-α-stimulated HT-29 cells. Subsequently, bacterial strains exhibiting antioxidant and anti-inflammatory properties were tested in vivo in a mouse model with dinitrobenzene sulfonic acid (DNBS)-induced chronic colitis. Weight loss, intestinal permeability, and cytokine profiles were measured in mice as indicators of inflammation. One of the selected strains, Lactobacillus plantarum LM17, improved the health of the mice, as observed by reduced weight loss, and significantly decreased intestinal permeability. Altogether, our results demonstrate the potential of LAB (and lactobacilli in particular) isolated from the agave fermentation stage in mezcal production. Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 strains represent potential candidates for developing new probiotic supplements to treat inflammatory bowel disease (IBD).