Luljeta Pinguli

The yeast performance, during the alcoholic fermentation, directly depends on its activity a function of the vitality and the physiological state of the viable cells. In order to undertake corrective actions before the inoculation process, it is important to predict the yeast vitality. Yeast vitality is the life span of the vegetative cells and their ability to reproduce. The most used method is the selective staining of the cells and then the averaging of results obtained in over 10 microscopic plots. The most used stain colors are methylene blue or methylene violet, which penetrate the damaged membranes of dead cells becoming stained, unable to penetrate the impermeable membranes of viable cells which remain transparent. The accepted level of vitality is 80% of viable cells, meanwhile the second and the third generations, which are highly adaptive rather than the first generation, may reach a vitality level up to 90%. A vitality analysis was carried out for the bottom-fermentation...

Proteins are a very important class of organic components in beer. They are long chains or polymers with large molecular weight composed from amino acids, connect to each other via peptide bonds. Quality and sustainability of beer depends on its protein content. Proteins play a very important role in many stages of brewing process. They are essential in the malt and wort production, also have a direct impact on the consistency and the formation of beer foam. This means the protein content in malt affect the quality of the finished product. It is very important to determine protein content before using malt for beer production. Malt is the main source of protein in beer. Proteins are made from compounds with nitrogen bases such as e.g. amino acids; every 1% nitrogen is equal to 6.25% protein. In this paper are the results of malt protein content in 2014,2015,2016 year. The amount of soluble protein or nitrogen, expressed in percentage by weight of malt and this indicator will be used...

The safety and quality of the final beer product depends not only on the fermentation process, but also on the quality of the raw materials used. Microbiological contamination of raw materials can lead to a premature spoilage of the beer, caused by spoilage bacteria, yeasts and molds, and gushing an unhealthy strong beer foaming caused by barley Fusarium spp. Water is an important raw material. It is used in malt steeping, boiling and even in the cleaning processes and beer containers, so it must meet the microbiological standard of drinking water. The ionic composition of water is also important for mashing, hop boiling, fermentation and contribution to beer flavor. The routine microbiological analysis is to ensure absence of pathogenic bacteria that are spread by contaminated water supplies. Hops or hop extracts have not actually been implicated in instances of contamination. The experimental work involved a general microbiological evaluation of raw materials using morphological a...

This work was based on the pretreatment of lingo-cellulosic wastes from agro – forestry organic wastes with samples being taken from stations of different sources. Between many of recommended and explained methods for pretreatment of the organic biomass we selected as the most effective, the way of acidic waste pretreatment and another scenario applying the alkaline method prior to the biodegradation through anaerobic bio-digestion for energy profit. For bio-methane profit process has been performed in a series of the experiments. From the various experiments we realized the great importance of the pre-treatment process for the biogas production. Alkaline pretreatment (with NaOH) brought about a decay of lignin structure of biomass and increase access of enzymes in hemicellulose and cellulose. This method was more effective than acidic treatment due to the fact that was achieved more dissolved lignocellulose, which is indicated by the highest decrease of organic material in the trea...

Microbial processes are highly dependent on temperature. This paper aims to study the influence of temperature on fermentation process on experimental and industrial scale. We were focused to determine the preexponential coefficients and the activation energy for experimental and industrial conditions and to quantify the amount of heat to be removed from fermenter to keep it under constant temperature during fermentation process. Substrate used for fermentation was beer industrial wort 12 Balling and yeast strain used was bottom fermentation yeast "Saccharomyces Carlsbegensis SP 35". Evaluation and comparison of kinetic parameters in different fermentation conditions were carried out. Temperatures used for different batches in industrial trials were 5, 20, 25 and 35 ° C and 8, 12 and 16 °C for experimental trials. Kinetic models developed were able to predict with a relatively high accuracy the experimental results achieved under non-thermal conditions and can be used to s...

The described experimental study, performed over the years, includes the quantitative and qualitative monitoring of the presence of microorganisms of air in outdoor and indoor environments of the Albanian Capital, Tirana, during a time when large demographic movements, accompanied by important urban interventions and infrastructural changes, have been part of our lives. A project, part of the National Program in Biotechnology (R & D—the year 2000), was the first support to obtain a database on microbiological air pollution in selected urban areas in Tirana and isolate and identify specific air microbial pollutants. The results obtained were an incentive to continue further with additional scientific evaluation monitoring research, which included the years 2011 to 2015 and then those of 2016–2020. Over the years, there has been a significant reduction in pollutant microbial loads (for selected outdoor areas of the center of Tirana, the total discovered loads decreased from values of ...

Pinguli, L., Troja, R., Malollari, I., Gurazi, V. & Vaso, T. (2020). A comparative study of free and immobilized brewing yeast fermentation performance based on kinetic parameters. Bulg. J. Agric. Sci., 26 (4), 899–905 The study was focused on comparing two different immobilized brewing yeast Saccharomyces carlsbergensis fermentations with traditional free cell fermentation in experimental scale. The immobilization techniques used were: entrapment and capsulation method in alginate support. The objective was to choose the most suitable immobilization technique that protects the yeast cells providing a good fermentation performance compared to free yeast cell fermentation. Kinetic parameters investigation of free and immobilized Saccharomyces carlsbergensis was done based on growth kinetics, ethanol productivity and substrate consumption (glucose) using computer simulation for different kinetic models. Entrapment and capsulation immobilization techniques are applicable, effective and...

The best practice for filtration optimization process is to control biological and non biological particles at every stage of beer chain production. There are several processes that can be used to control beer filtration process, such as settlement of non-biological and biological particles through sedimentation, centrifugation, extended stabilization periods, addition of flocculants and clarifiers to reduce both, yeast and haze loadings etc. Filtration process is controlled by yeast, proteins and carbohydrates. Cell yeast number in suspension determines which is going to dominate filtration process. If yeast cell number is less than a million, filterability is dependent mainly from physico-chemical beer characteristics, otherwise biological phase control filtration process. In this paper we have proposed some enzymatic and yeast management techniques to improve filtration process. Experiments were carried out in laboratory and industrial scale. There were used free and immobilized ...