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The Influence of Germinated Hull-less Barley Sordough Fermentation Conditions on the Microbiota Development Texto completo
2021
Kl̦ava, Dace | Poisa, Iveta | Reidzane, Sanita | Kince, Tatjana | Kazantseva, Jekaterina | Traksmaa, Anna
Sourdough plays an important role in quality assurance, especially during developing wholegrain wheat bread products. The value of barley and hull-less barley grains is determined by the low lipid and high carbohydrate (starch and resistant starch) content, balanced amino acid profile, dietary fibre and phenolic compounds. During germination (24 h) the amount of sugar, amino acids and vitamins increase in the grains. Therefore, it could be optimal environment for microbiota growth in sourdough. The goal of the research was to find optimal technological parameters and to study microorganism growth dynamic during the fermentation of sourdough with germinated hull-less barley. The study was performed using three steps of fermentation, with different temperature and time parameters. At each step pH, dynamics of lactic acid bacteria (LAB), yeast-like fungi and total plate count (TPC) growth were determined using standard methods. The results of the study showed that the optimal fermentation conditions for the first stage are 48 h and 26 ± 1 °C, for the second stage 8 h and 26 ± 1 °C and for the third stage 20 h and 28 ± 1 °C. During fermentation of the sourdough, the pH 3.91 is reached, LAB 8.8 log₁₀ CFU g⁻¹, and the yeast-like fungi 8.7 log₁₀ CFU g⁻¹ was determined. Obtained data show that more than 80 bacteria and 50 microscopic fungal species were detected in hull-less barley flour, but after germination their diversity decreased and in the germinated hull-less barley sourdoughs dominated species were Pediococcus pentosaceus.
Mostrar más [+] Menos [-]Theoretical and Experimental Investigation of the Thermal Inactivation of Thermoanaerobacterium Thermosaccharolyticum and Geobacillus Stearothermophilus in Different Canned Food Matrices Texto completo
2021
Raits, Evalds | Raita, Svetlana | Kirse-Ozolina, Asnate | Muizniece-Brasava, Sandra
In the canning industry, thermal preservation processes typically are designed based on Clostridium botulinum thermal destruction kinetics. However, some bacteria can still survive, necessitating implementation of stricter timetemperature regimen for sterilization process. The aim of this study was to compare processing effectiveness at F₀ (sterilization value) 8 ±1 min from the perspective of the vegetable-based product canning facility, while analyzing the inactivation, viability, and recovery of thermophilic bacteria. Four commercial products [tomato soup and rassolnik soup - acidified food (AF), and mushroom soup and pea porridge - low-acid food (LACF)] with different heat transfer characteristics (convection and conduction) were inoculated with 6.6 log₁₀ spores/ml Geobacillus stearothermophilus LMKK 244 (reported as DSM 6790 and ATCC 10149 in other collections) and 4.8₁₀ log spores/ml Thermoanaerobacterium thermosaccharolyticum DSM 571 spore suspensions. Food samples contaminated with bacterial spores were processed in a steam-air retort at 118 °C for 75 min. G. stearothermophilus and T. thermosaccharolyticum growth was not detected in AF samples (pH = 4.4 and 4.5), but was observed in LACF samples (pH = 5.1 and 5.8). Practical evaluation showed that T. thermosaccharolyticum did not survive thermal processing, which was verified using a presence/absence test after incubation at 55 °C. G. stearothermophilus did not survive thermal processing, but recovered in pea porridge (pH = 5.8) during incubation. Our observations showed that food pH is a crucial factor determining microorganism survival during heat treatment and may be used by the vegetable-based product canning facilities to improve the food sterilization conditions.
Mostrar más [+] Menos [-]Slaughter Results, Meat Chemical Composition and pH of Aberdinangus, Hereford and Limousin bulls Texto completo
2021
Muizniece, Inga | Kairisa, Daina
Beef production must combine the interests of both producers and consumers, taking into account the sustainable use of environmental resources. The aim of the study was to analyze and compare the slaughter results, meet chemical composition and pH value of three beef breeds – Aberdinangus (AA), Hereford (HF) and Limousin (LI) bulls. The bulls were fattened on Latvian and Lithuanian farms, mainly using grass forage. The breed and age of bulls before slaughter significantly affected all slaughter results, except for fat class. From the meat chemical composition traits, the bull breed and age before slaughter had a significant effect only on the protein content. LI bulls showed the highest carcass weight 301.1±6.8 kg (p<0.05), dressing percentage 58.2±1.1% (p<0.05) and conformation score 3.56±0.18 points. The best fattened carcasses were obtained from AA bulls - 2.43±0.20 points. Muscle samples of musculus longissimus (M. longissimus) bulls of LI breed showed higher content of moisture (72.0±1.0%), protein (23.0±0.2%), ash (1.1±0.0%) and cholesterol (56.7±6.6 mg 100 g⁻¹). AA breed bulls showed higher total fat (6.6±1.2%) and iron content (13.1±0.6 mg). The highest pH was observed in the meat obtained from AA bulls – 6.0±0.1, LI and HF breed bulls showed pH 5.8±0.0 and 5.8±0.1 respectively. Correlation analysis showed a significant, strong positive correlation between cold carcass weight and dressing percentage for AA and LI bulls, r=0.90 and r=0.88, respectively. For LI breed bulls, a strong positive correlation was also found between the cold carcass weight and the conformation score (r=0.98, p<0.01).
Mostrar más [+] Menos [-]The Influence of Technological Peculiarities on Fermented Sausages’ Quality and Sensory Properties Texto completo
2021
Gramatina, Ilze | Sauka, Janis | Semjonovs, Aleksandrs | Strode, Sintija | Straumite, Evita
Fermentation is one of the ancient technological processes used in food production which influences the shelf-life of meat and meat products, also significantly affects the sensory properties like aroma and flavour. The objective of the present study was to evaluate the elaborated technology for a new fermented sausage production on the product quality and sensory properties. Sausages were produced by the standard technology using glucono-delta-lactone or starter culture. The drying of samples differs from 3 to 4 weeks at the same conditions; samples were dried for 4 weeks which produced with the starter culture, and 3 weeks which produced with glucono-delta-lactone. The sausages were tested at the end of the production, analysing pH, water activity, moisture and salt content, as well as the presence of Listeria monocytogenes, colony forming units of Listeria monocytogenes and Enterobacteriaceae in the sausage samples were analysed. The sensory evaluation was organised after getting Listeria monocytogenes testing results. The moisture content, water activity and salt content significantly differed (p < 0.05) among samples, no differences were established in pH, taste and flavour liking. The presence of Listeria monocytogenes was not established in samples which indicates that the producer properly applies a hurdle technology in fermented sausage production. Sensory evaluation results showed higher scores for texture and appearance in fermented sausages with glucono-delta-lactone. The study results confirmed that fermented sausages with glucono-delta-lactone during 3 weeks of drying can achieve corresponding safety criteria and sensory properties which are set for semidry fermented sausages.
Mostrar más [+] Menos [-]Pre-treatment Effect on Physical and Microbial Parameters of Smoked Baltic Sprats Texto completo
2021
Puke, Santa | Galoburda, Ruta
Smoked sprats are delicious and nutritionally valuable product. Besides protein, it contains high amount of unsaturated fatty acids and fat soluble vitamins. Nowadays, human interest for fish product consumption is increasing. It leads to the demand for increased shelf life of the smoked sprats. One way to prolong the shelf life is to use some pre-treatment prior to smoking. The aim of study was to analyse the effect of pre-treatment on smoked Baltic sprat quality and microbiological parameters. Various compositions of brine using salts (NaCl, CaCl₂) and acetic acid in different proportions were used for fresh sprat pre-treatment. Pre-treatment had the influence on physical parameters; pre-treated samples had higher salt and lower moisture content, and lower pH, which allowed prolonging the shelf life of smoked sprats. The highest pH was in the control sample 6.6, and it allowed growth of yeasts, moulds, Pseudomonas spp., and mesophilic and facultative anaerobic microorganisms. The results demonstrated that after two-week storage of the smoked sprats the growth of moulds (1×10² CFU g⁻¹) was observed only for smoked sprats without pre-treatment (control sample), indicating the positive effect of pre-treatment. Salmonella spp., Clostridium perfingens, Listeria monocytogenes, and Escherichia coli were not detected in any of the analysed samples. After pre-treatment in brine, containing combination of NaCl and CaCl₂, smoked fish had darker colour compared to control sample or sample with sodium chloride only. Any of applied pre-treatments, except brine containing NaCl, made firmer texture of the smoked fish.
Mostrar más [+] Menos [-]The Characteristics of Extruded Faba Beans (Vicia faba L.) Texto completo
2016
Liene, Strauta | Sandra, Muižniece-Brasava
Faba beans (Vicia faba L.) are an excellent protein source and should be more present in human diet, but due to their long cooking time, they are rarely used. So, in order to increase the accessibility of faba beans (Vicia faba L.), experiments were carried out to obtain new food products. Extrusion-cooking was chosen as the potential thermal cooking process and two different products were obtained. One was made exclusively from faba bean (Vicia faba L.) flour, while the second one was produced with a 50% addition of wheat flour to bean flour. Protein content, size, volume mass, pH and starch content for obtained products were analysed in order to characterise the products, as well as to see the differences from non-extruded faba beans (Vicia faba L.) and obtained samples. The experiments were carried out using faba beans (Vicia faba L.) obtained at Ltd. “Pure Horticultural Research Centre”. They were milled at Ltd. “Grauda spēks” and extruded with a twin screw extruder at Ltd. “Milzu”. The experiments showed that the extrusion process had decreased the protein content by 9%, but the starch content had risen by 13% with the addition of wheat flour. But, for sample, without added wheat flour differences were not significant. No significant size differences were observed in the obtained samples and pH values had no significant differences between extruded samples.
Mostrar más [+] Menos [-]Study of amino acid profile and solubility of pea protein isolate for the production of beverages for psychiatric patients Texto completo
2024
Plocina, Lasma | Beitane, Ilze
Excessive intake of saturated fatty acids and physiologically imbalanced amino acids worsens the patient’s psychotic condition, creating the risk of developing psychosis and other comorbidities. Therefore, to ensure the optimal amount of amino acids and improve the psychotic state, pea protein isolate is an alternative to nutritional supplementation. The aim of the study was to analyse the amino acid profile of pea protein isolates and their solubility to evaluate their potential for the development of beverages for patients with psychiatric disorders. In the study, the amino acid profile analysis of organic and conventional pea protein isolates was performed using high performance liquid chromatography mass spectrometry. To evaluate solubility, pea protein isolates were treated in an ultrasonic bath and at different pH concentrations. The results showed that organic pea protein isolate showed a higher composition of essential amino acids (41.27%) and semi-essential amino acids (8.37%) than conventional pea protein isolate. Organic pea protein isolate was able to provide a more appropriate amino acid composition to meet the amino acid needs of patients with psychiatric disorders. Organic and conventional pea protein isolates had higher solubility in the ultrasonic bath of 20 min and in the alkaline environment. The solubility between the two pea protein isolates was not significantly different, but the ultrasonic bath treatment and different pH concentrations were significant, which gave insight and further application in beverage production.
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