Katarzyna Skrzypczak - Academia.edu (original) (raw)

Papers by Katarzyna Skrzypczak

Zywnosc Nauka Technologia Jakosc/Food Science Technology Quality, 2018

Technologia sous-vide została opracowana w 1974 roku przez francuskiego kucharza Georgesa Pralusa... more Technologia sous-vide została opracowana w 1974 roku przez francuskiego kucharza Georgesa Pralusa, ale dopiero w ostatnich latach zyskała miano nowoczesnego sposobu obróbki cieplej surowców pochodzenia roślinnego i zwierzęcego. Jest to proces gotowania w ściśle kontrolowanej temperaturze i w określonym czasie surowców spożywczych zapakowanych próżniowo. Istotne jest użycie surowców najwyższej jakości. Po zakończeniu gotowania żywność poddaje się szybkiemu schłodzeniu i przechowuje w niskiej temperaturze. Przed ekspedycją produkty chłodzone i mrożone poddaje się restytucji. Temperatura procesu odgrzewania powinna być podobna lub niższa od użytej w trakcie procesu pasteryzacji. Jednoczesne zastosowanie kilku czynników utrwalających, tj. modyfikowanej atmosfery przechowywania, pasteryzacji oraz przechowywania w warunkach chłodniczych umożliwia działanie addytywne i znacząco wpływa na jakość produktu w trakcie przechowywania. Warunki panujące podczas poszczególnych etapów (pakowanie pró...

International Journal of Molecular Sciences, 2021

The production of mead holds great value for the Polish liquor industry, which is why the bacteri... more The production of mead holds great value for the Polish liquor industry, which is why the bacterium that spoils mead has become an object of concern and scientific interest. This article describes, for the first time, Lactobacillus hilgardii FLUB newly isolated from mead, as a mead spoilage bacteria. Whole genome sequencing of L. hilgardii FLUB revealed a 3 Mbp chromosome and five plasmids, which is the largest reported genome of this species. An extensive phylogenetic analysis and digital DNA-DNA hybridization confirmed the membership of the strain in the L. hilgardii species. The genome of L. hilgardii FLUB encodes 3043 genes, 2871 of which are protein coding sequences, 79 code for RNA, and 93 are pseudogenes. L. hilgardii FLUB possesses three clustered regularly interspaced short palindromic repeats (CRISPR), eight genomic islands (44,155 bp to 6345 bp), and three (two intact and one incomplete) prophage regions. For the first time, the characteristics of the genome of this speci...

Acta Universitatis Cibiniensis. Series E: Food Technology, 2020

In the present study, the physicochemical, textural and sensorial properties of crackerbread (mad... more In the present study, the physicochemical, textural and sensorial properties of crackerbread (made from rye, maize and wheat flour) and rice waffles, the most popular on the Polish market bread substitutes, were determined. It was shown that values of several mechanical properties of rice waffles, including ultimate fracture force, strain and stress differed significantly from that of crackerbread. Texture profile analysis showed that the highest hardness and springiness was exhibited by rice waffles with sesame seeds and wheat-rye, respectively. The concentration of salt was the lowest in rice bread with sunflower. The most acceptable was the rice bread with sea salt (8.26 in a 9-point scale) and overall consumer acceptance of crispbreads was highly correlated with sensory attribute of saltiness.

Zeszyty Problemowe Postępów Nauk Rolniczych, 2019

Some strains of lactic acid bacteria (LAB) possess an ability to produce exopolysaccharides (EPS)... more Some strains of lactic acid bacteria (LAB) possess an ability to produce exopolysaccharides (EPS). Presence of these biopolymers in fermented milk products contributes to improvement of consistency and stability of the nal products. This study investigated the effect of whey protein preparations on the rheological properties of yoghurt fermented by starter cultures able to EPS production. The addition of whey protein preparations into milk during yoghurt production stimulates the secretion of EPS by LAB and effects on increase viscosity of products. The highest concentrations of EPS were obtained in products containing 0.5% addition of whey powder (WP)-127.8 mg/100 ml or 134.6 mg/100 ml of yoghurt containing different culture. At higher WP concentration negatively affected on consistency of yoghurts was observed. Inverse tendency was observed in products containing WPI. The obtained results suggest milk products fermented by cultures producing EPS combined with whey protein preparations supplementation may lead to new products considered as functional food.

International Journal of Food Science, 2021

The objective of this investigation was to verify whether biologically active peptides (BAPs) cou... more The objective of this investigation was to verify whether biologically active peptides (BAPs) could be obtained from water solutions of α-lactalbumin (α-la) and caseinoglycomacropeptide (CGMP) through an application of the new Lactobacillus helveticus strains. Also, the aim of this research was to determine the influence of addition of the analyzed protein preparations to milk subjected to fermentation by tested bacterial strains on the physicochemical properties of obtained milk beverages. The results indicate that CGMP is a more preferable source for the production of BAPs by the test bacteria than α-la. The antihypertensive and ACE inhibitory effects were the most widespread bioactivities among the detected BAPs. α-la containing fermented milk beverages had higher values of springiness, gumminess, chewiness, and resilience than analogous products containing CGMP, while CGMP-supplemented fermented products exhibited higher values of the hardness parameter. The highest values of ha...

Foods, 2021

This study is a brief report on the proteolytic activity of curly kale leaf extract against casei... more This study is a brief report on the proteolytic activity of curly kale leaf extract against casein. Casein degradation products and an in silico analysis of the biological activity of the peptides obtained was performed. The efficiency of casein hydrolysis by curly kale extract was determined using SDS–PAGE and by peptide concentration determination. The pattern of the enzymatic activity was determined by MALDI–TOF MS analysis. The results showed that α- and β-casein were more resistant to curly kale extract hydrolysis, whereas κ-casein was absent in the protein profile after 8 h of proteolysis, and all casein fractions were completely hydrolyzed after 24 h of incubation. Based on sequence analysis, seven peptides were identified, with molecular mass in the range of 1151–3024 Da. All the peptides were products of β-casein hydrolysis. The identified amino acid sequences were analyzed in BIOPEP, MBPDB, and FeptideDB databases in order to detect the potential activities of the peptides...

Acta Universitatis Cibiniensis. Series E: Food Technology, 2021

The study investigated the suitability of a novel strain Lactiplantibacillus plantarum EK11 for o... more The study investigated the suitability of a novel strain Lactiplantibacillus plantarum EK11 for obtaining fermented tomato and beetroot juices with improved functional potential. EK11 had the capability of dynamic acidification of pasteurized vegetable beverages. The lowest values of pH were noted in juices after 48 h of fermentation with the probiotic L. plantarum 299v (pH=3.72±0.01 in beet juice and pH=3.43±.0.01 in tomato juice). The fermentation increased the lycopene content in tomato juices from 27.90±0.31µg mL−1 (after 24-h fermentation by strain EK11) to 116.86 ±0.19 µg mL−1 (final products obtained using strain 299v after 7-day cold storage). The process contributed to changes in the betanin and vulgaxanthin-I concentration in beetroot beverages. All fermented products exhibited antioxidative activity, i.e. 50% inhibition of 1,1-diphenyl-2-picrylhydrazyl free radicals. Moreover, three genes involved in the biosynthesis of bacteriocins were detected in the novel strain EK11,...

Applied Sciences, 2020

With their desired functional and technological properties, whey protein preparations are used in... more With their desired functional and technological properties, whey protein preparations are used in the food industry. In turn, lactic acid fermentation may contribute to release of a wide range of biologically active peptides (BAPs) (known also as bioactive peptides or biopeptides) from whey and milk proteins, which are perceived as potential therapeutic tools and important constituents of personalized food suitable for prevention of many civilization and diet-related diseases. Therefore, the objective of this study was to determine the suitability of new Lb. helveticus strains for production of fermented milk beverages (drinking type) supplemented with whey protein isolate (WPI). Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) was employed to assess if WPI (water solution) might be a suitable precursor for BAPs produced by selected strains of Lb. helveticus. In order to identify the bioactivities of the peptides generated in WPI hydrolysates, the procedures indicat...

The objective of this study was to compare the effect of probiotic fermentation (conducted by L. ... more The objective of this study was to compare the effect of probiotic fermentation (conducted by L. acidophilus LA-5) of milk containing an addition of selected whey or milk protein preparations (whey protein concentrates, whole milk, whey protein isolate, casein glycomacropeptide or α-lactalbumin) on the technological and functional properties of obtained milk beverages. Determination of the antioxidative activities and identification sequences of biologically active peptides generated in selected protein preparations during probiotic fermentation also constituted the aim of the research. The results obtained indicate that the addition (1%) of α-lactalbumin into regenerated skimmed milk in the highest degree reduced the syneresis level in fermented products. Also, αlactalbumin hydrolysates exhibited the strongest antioxidative properties (57.57±6.6%), while casein glycomacropeptide hydrolysates allowed us to obtain the highest amount of various biopeptides.

Microbial Production of Food Ingredients and Additives

Foods

The aim of the investigation was the identification and initial study of lactic acid bacteria (LA... more The aim of the investigation was the identification and initial study of lactic acid bacteria (LAB) isolated from spontaneously fermented (at 28 °C for 5 days) fruiting bodies of white button mushrooms (Agaricus bisporus). The isolated LAB were preliminarily characterized applying the MALDI-TOF Biotyper. Moreover, further phenotypical, genotypical characteristics as well as some functional and technological properties of the selected microorganisms (including the ability to produce exopolysaccharides, cell hydrophobicity, resistance to low pH, and bile salt) were also analyzed. Among autochthonous LAB (isolated from the tested mushroom raw material), Leuconostoc mesenteroides predominated in spontaneously fermented A. bisporus, while Lactiplantibacillus paraplantarum, Lactiplantibacillus plantarum, and Lactococcus lactis were less abundant. The highest dynamics of acidification of the mushroom material were exhibited by isolates EK55 and EK4 that, after 24 h of incubation, were able...

Applied Sciences

This paper reports the potential use of fermented curly kale juice in Feta-type cheese production... more This paper reports the potential use of fermented curly kale juice in Feta-type cheese production. The rheological study and Turbiscan assay demonstrated that fermented curly kale juice coupled with rennet accelerated curd formation resulted in a stronger curd compared to the sample containing rennet alone. Laboratory-scale cheese was manufactured from cow’s milk with the use of fermented curly kale juice. Several parameters that affect the quality of cheese were investigated, including physicochemical, textural and microstructure characteristics. The content of amino acids and fatty acids was determined, surface properties were assessed and microbial enumeration of the experimental cheese was carried out before and after ripening. The values of pH and the content of lactose and protein significantly decreased as a result of maturation. In turn, an increase in LAB growth as well as saturated and unsaturated fatty acids was observed. The use of the fermented curly kale juice improved...

Journal of Pure and Applied Microbiology

Applied Sciences

Water soluble polysaccharides (WSP) were isolated from Lentinus edodes fruiting bodies. The mushr... more Water soluble polysaccharides (WSP) were isolated from Lentinus edodes fruiting bodies. The mushrooms were previously subjected to various processing techniques which included blanching, boiling, and fermenting with lactic acid bacteria. Therefore, the impact of processing on the content and biological activities of WSP was established. Non-processed fruiting bodies contained 10.70 ± 0.09 mg/g fw. Boiling caused ~12% decrease in the amount of WSP, while blanched and fermented mushrooms showed ~6% decline. Fourier transform infrared spectroscopy analysis (FTIR) confirmed the presence of β-glycosidic links, whereas due to size exclusion chromatography 216 kDa and 11 kDa molecules were detected. WSP exhibited antioxidant potential in FRAP (ferric ion reducing antioxidant power) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays. Cytotoxic properties were determined on MCF-7 and T47D human breast cell lines using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetraz...

Czech Journal of Food Sciences

The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 a... more The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 and DSMZ 20075) and Lactobacillus acidophilus La-05 (probiotic strain) on the antioxidant activity of whey and milk protein preparations. In order to indicate possible mechanism of antioxidant activity of the obtained hydrolysates, the reducing power (RP) assay, ability to neutralize free radicals and Fe2+ chelating activity analysis were employed. The results suggest that antioxidant activity of tested hydrolysates depends on the type of protein preparation (substrate) and the applied bacterial strain. The strongest antioxidant activity was exhibited by whey protein isolate hydrolysate obtained by using L. helveticus T80. A majority of fermented products obtained with the use of the probiotic strain were characterized by higher antioxidant properties than those obtained by application of L. helveticus. The solution of caseinoglicomacropeptide fermented by strain T105 exhibited the highes...

Polish Journal of Microbiology

Most of the lactic acid bacteria (LAB) are able to grow in milk mainly due to the activity of a c... more Most of the lactic acid bacteria (LAB) are able to grow in milk mainly due to the activity of a complex and well-developed proteolytic system. Cell envelope-associated proteinases (CEPs) begin casein hydrolysis and allow for releasing the peptides, enclosed in the structure of native milk proteins that are essential for growth of Lactobacillus helveticus. The biodiversity of genes encoding CEPs among L. helveticus strains can have an effect on some technological parameters such as acid production, bacterial growth rate in milk as well as liberation of biologically active peptides. The study reveals significant differences in the presence of various variants of CEPs encoding genes among ten novel Polish strains and indicates the intraspecific diversity exhibited by L. helveticus. In terms of distribution of CEPs genes, four different genetic profiles were found among the microorganisms analyzed. Furthermore, the strains exhibited also various levels of proteolytic activity. Molecular analysis revealed that prtH3 is the most abundant CEPs-encoding gene among the strains investigated. The results indicate also that ecological niche and environmental conditions might affect proteolytic properties of L. helveticus strains. The greatest variety in terms of quantity of the detected CEP encoding genes was noticed in L. helveticus 141, T105 and T104 strains. In these strains, the combination of three nucleotide gene sequences (prtH/prtH2/prtH3) was identified. Interestingly, T104 and T105 exhibited the highest proteolytic activity and also the fastest dynamic of milk acidification among the tested strains of L. helveticus.

Zywnosc Nauka Technologia Jakosc/Food Science Technology Quality, 2018

Technologia sous-vide została opracowana w 1974 roku przez francuskiego kucharza Georgesa Pralusa... more Technologia sous-vide została opracowana w 1974 roku przez francuskiego kucharza Georgesa Pralusa, ale dopiero w ostatnich latach zyskała miano nowoczesnego sposobu obróbki cieplej surowców pochodzenia roślinnego i zwierzęcego. Jest to proces gotowania w ściśle kontrolowanej temperaturze i w określonym czasie surowców spożywczych zapakowanych próżniowo. Istotne jest użycie surowców najwyższej jakości. Po zakończeniu gotowania żywność poddaje się szybkiemu schłodzeniu i przechowuje w niskiej temperaturze. Przed ekspedycją produkty chłodzone i mrożone poddaje się restytucji. Temperatura procesu odgrzewania powinna być podobna lub niższa od użytej w trakcie procesu pasteryzacji. Jednoczesne zastosowanie kilku czynników utrwalających, tj. modyfikowanej atmosfery przechowywania, pasteryzacji oraz przechowywania w warunkach chłodniczych umożliwia działanie addytywne i znacząco wpływa na jakość produktu w trakcie przechowywania. Warunki panujące podczas poszczególnych etapów (pakowanie pró...

International Journal of Molecular Sciences, 2021

The production of mead holds great value for the Polish liquor industry, which is why the bacteri... more The production of mead holds great value for the Polish liquor industry, which is why the bacterium that spoils mead has become an object of concern and scientific interest. This article describes, for the first time, Lactobacillus hilgardii FLUB newly isolated from mead, as a mead spoilage bacteria. Whole genome sequencing of L. hilgardii FLUB revealed a 3 Mbp chromosome and five plasmids, which is the largest reported genome of this species. An extensive phylogenetic analysis and digital DNA-DNA hybridization confirmed the membership of the strain in the L. hilgardii species. The genome of L. hilgardii FLUB encodes 3043 genes, 2871 of which are protein coding sequences, 79 code for RNA, and 93 are pseudogenes. L. hilgardii FLUB possesses three clustered regularly interspaced short palindromic repeats (CRISPR), eight genomic islands (44,155 bp to 6345 bp), and three (two intact and one incomplete) prophage regions. For the first time, the characteristics of the genome of this speci...

Acta Universitatis Cibiniensis. Series E: Food Technology, 2020

In the present study, the physicochemical, textural and sensorial properties of crackerbread (mad... more In the present study, the physicochemical, textural and sensorial properties of crackerbread (made from rye, maize and wheat flour) and rice waffles, the most popular on the Polish market bread substitutes, were determined. It was shown that values of several mechanical properties of rice waffles, including ultimate fracture force, strain and stress differed significantly from that of crackerbread. Texture profile analysis showed that the highest hardness and springiness was exhibited by rice waffles with sesame seeds and wheat-rye, respectively. The concentration of salt was the lowest in rice bread with sunflower. The most acceptable was the rice bread with sea salt (8.26 in a 9-point scale) and overall consumer acceptance of crispbreads was highly correlated with sensory attribute of saltiness.

Zeszyty Problemowe Postępów Nauk Rolniczych, 2019

Some strains of lactic acid bacteria (LAB) possess an ability to produce exopolysaccharides (EPS)... more Some strains of lactic acid bacteria (LAB) possess an ability to produce exopolysaccharides (EPS). Presence of these biopolymers in fermented milk products contributes to improvement of consistency and stability of the nal products. This study investigated the effect of whey protein preparations on the rheological properties of yoghurt fermented by starter cultures able to EPS production. The addition of whey protein preparations into milk during yoghurt production stimulates the secretion of EPS by LAB and effects on increase viscosity of products. The highest concentrations of EPS were obtained in products containing 0.5% addition of whey powder (WP)-127.8 mg/100 ml or 134.6 mg/100 ml of yoghurt containing different culture. At higher WP concentration negatively affected on consistency of yoghurts was observed. Inverse tendency was observed in products containing WPI. The obtained results suggest milk products fermented by cultures producing EPS combined with whey protein preparations supplementation may lead to new products considered as functional food.

International Journal of Food Science, 2021

The objective of this investigation was to verify whether biologically active peptides (BAPs) cou... more The objective of this investigation was to verify whether biologically active peptides (BAPs) could be obtained from water solutions of α-lactalbumin (α-la) and caseinoglycomacropeptide (CGMP) through an application of the new Lactobacillus helveticus strains. Also, the aim of this research was to determine the influence of addition of the analyzed protein preparations to milk subjected to fermentation by tested bacterial strains on the physicochemical properties of obtained milk beverages. The results indicate that CGMP is a more preferable source for the production of BAPs by the test bacteria than α-la. The antihypertensive and ACE inhibitory effects were the most widespread bioactivities among the detected BAPs. α-la containing fermented milk beverages had higher values of springiness, gumminess, chewiness, and resilience than analogous products containing CGMP, while CGMP-supplemented fermented products exhibited higher values of the hardness parameter. The highest values of ha...

Foods, 2021

This study is a brief report on the proteolytic activity of curly kale leaf extract against casei... more This study is a brief report on the proteolytic activity of curly kale leaf extract against casein. Casein degradation products and an in silico analysis of the biological activity of the peptides obtained was performed. The efficiency of casein hydrolysis by curly kale extract was determined using SDS–PAGE and by peptide concentration determination. The pattern of the enzymatic activity was determined by MALDI–TOF MS analysis. The results showed that α- and β-casein were more resistant to curly kale extract hydrolysis, whereas κ-casein was absent in the protein profile after 8 h of proteolysis, and all casein fractions were completely hydrolyzed after 24 h of incubation. Based on sequence analysis, seven peptides were identified, with molecular mass in the range of 1151–3024 Da. All the peptides were products of β-casein hydrolysis. The identified amino acid sequences were analyzed in BIOPEP, MBPDB, and FeptideDB databases in order to detect the potential activities of the peptides...

Acta Universitatis Cibiniensis. Series E: Food Technology, 2021

The study investigated the suitability of a novel strain Lactiplantibacillus plantarum EK11 for o... more The study investigated the suitability of a novel strain Lactiplantibacillus plantarum EK11 for obtaining fermented tomato and beetroot juices with improved functional potential. EK11 had the capability of dynamic acidification of pasteurized vegetable beverages. The lowest values of pH were noted in juices after 48 h of fermentation with the probiotic L. plantarum 299v (pH=3.72±0.01 in beet juice and pH=3.43±.0.01 in tomato juice). The fermentation increased the lycopene content in tomato juices from 27.90±0.31µg mL−1 (after 24-h fermentation by strain EK11) to 116.86 ±0.19 µg mL−1 (final products obtained using strain 299v after 7-day cold storage). The process contributed to changes in the betanin and vulgaxanthin-I concentration in beetroot beverages. All fermented products exhibited antioxidative activity, i.e. 50% inhibition of 1,1-diphenyl-2-picrylhydrazyl free radicals. Moreover, three genes involved in the biosynthesis of bacteriocins were detected in the novel strain EK11,...

Applied Sciences, 2020

With their desired functional and technological properties, whey protein preparations are used in... more With their desired functional and technological properties, whey protein preparations are used in the food industry. In turn, lactic acid fermentation may contribute to release of a wide range of biologically active peptides (BAPs) (known also as bioactive peptides or biopeptides) from whey and milk proteins, which are perceived as potential therapeutic tools and important constituents of personalized food suitable for prevention of many civilization and diet-related diseases. Therefore, the objective of this study was to determine the suitability of new Lb. helveticus strains for production of fermented milk beverages (drinking type) supplemented with whey protein isolate (WPI). Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) was employed to assess if WPI (water solution) might be a suitable precursor for BAPs produced by selected strains of Lb. helveticus. In order to identify the bioactivities of the peptides generated in WPI hydrolysates, the procedures indicat...

The objective of this study was to compare the effect of probiotic fermentation (conducted by L. ... more The objective of this study was to compare the effect of probiotic fermentation (conducted by L. acidophilus LA-5) of milk containing an addition of selected whey or milk protein preparations (whey protein concentrates, whole milk, whey protein isolate, casein glycomacropeptide or α-lactalbumin) on the technological and functional properties of obtained milk beverages. Determination of the antioxidative activities and identification sequences of biologically active peptides generated in selected protein preparations during probiotic fermentation also constituted the aim of the research. The results obtained indicate that the addition (1%) of α-lactalbumin into regenerated skimmed milk in the highest degree reduced the syneresis level in fermented products. Also, αlactalbumin hydrolysates exhibited the strongest antioxidative properties (57.57±6.6%), while casein glycomacropeptide hydrolysates allowed us to obtain the highest amount of various biopeptides.

Microbial Production of Food Ingredients and Additives

Foods

The aim of the investigation was the identification and initial study of lactic acid bacteria (LA... more The aim of the investigation was the identification and initial study of lactic acid bacteria (LAB) isolated from spontaneously fermented (at 28 °C for 5 days) fruiting bodies of white button mushrooms (Agaricus bisporus). The isolated LAB were preliminarily characterized applying the MALDI-TOF Biotyper. Moreover, further phenotypical, genotypical characteristics as well as some functional and technological properties of the selected microorganisms (including the ability to produce exopolysaccharides, cell hydrophobicity, resistance to low pH, and bile salt) were also analyzed. Among autochthonous LAB (isolated from the tested mushroom raw material), Leuconostoc mesenteroides predominated in spontaneously fermented A. bisporus, while Lactiplantibacillus paraplantarum, Lactiplantibacillus plantarum, and Lactococcus lactis were less abundant. The highest dynamics of acidification of the mushroom material were exhibited by isolates EK55 and EK4 that, after 24 h of incubation, were able...

Applied Sciences

This paper reports the potential use of fermented curly kale juice in Feta-type cheese production... more This paper reports the potential use of fermented curly kale juice in Feta-type cheese production. The rheological study and Turbiscan assay demonstrated that fermented curly kale juice coupled with rennet accelerated curd formation resulted in a stronger curd compared to the sample containing rennet alone. Laboratory-scale cheese was manufactured from cow’s milk with the use of fermented curly kale juice. Several parameters that affect the quality of cheese were investigated, including physicochemical, textural and microstructure characteristics. The content of amino acids and fatty acids was determined, surface properties were assessed and microbial enumeration of the experimental cheese was carried out before and after ripening. The values of pH and the content of lactose and protein significantly decreased as a result of maturation. In turn, an increase in LAB growth as well as saturated and unsaturated fatty acids was observed. The use of the fermented curly kale juice improved...

Journal of Pure and Applied Microbiology

Applied Sciences

Water soluble polysaccharides (WSP) were isolated from Lentinus edodes fruiting bodies. The mushr... more Water soluble polysaccharides (WSP) were isolated from Lentinus edodes fruiting bodies. The mushrooms were previously subjected to various processing techniques which included blanching, boiling, and fermenting with lactic acid bacteria. Therefore, the impact of processing on the content and biological activities of WSP was established. Non-processed fruiting bodies contained 10.70 ± 0.09 mg/g fw. Boiling caused ~12% decrease in the amount of WSP, while blanched and fermented mushrooms showed ~6% decline. Fourier transform infrared spectroscopy analysis (FTIR) confirmed the presence of β-glycosidic links, whereas due to size exclusion chromatography 216 kDa and 11 kDa molecules were detected. WSP exhibited antioxidant potential in FRAP (ferric ion reducing antioxidant power) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays. Cytotoxic properties were determined on MCF-7 and T47D human breast cell lines using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetraz...

Czech Journal of Food Sciences

The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 a... more The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 and DSMZ 20075) and Lactobacillus acidophilus La-05 (probiotic strain) on the antioxidant activity of whey and milk protein preparations. In order to indicate possible mechanism of antioxidant activity of the obtained hydrolysates, the reducing power (RP) assay, ability to neutralize free radicals and Fe2+ chelating activity analysis were employed. The results suggest that antioxidant activity of tested hydrolysates depends on the type of protein preparation (substrate) and the applied bacterial strain. The strongest antioxidant activity was exhibited by whey protein isolate hydrolysate obtained by using L. helveticus T80. A majority of fermented products obtained with the use of the probiotic strain were characterized by higher antioxidant properties than those obtained by application of L. helveticus. The solution of caseinoglicomacropeptide fermented by strain T105 exhibited the highes...

Polish Journal of Microbiology

Most of the lactic acid bacteria (LAB) are able to grow in milk mainly due to the activity of a c... more Most of the lactic acid bacteria (LAB) are able to grow in milk mainly due to the activity of a complex and well-developed proteolytic system. Cell envelope-associated proteinases (CEPs) begin casein hydrolysis and allow for releasing the peptides, enclosed in the structure of native milk proteins that are essential for growth of Lactobacillus helveticus. The biodiversity of genes encoding CEPs among L. helveticus strains can have an effect on some technological parameters such as acid production, bacterial growth rate in milk as well as liberation of biologically active peptides. The study reveals significant differences in the presence of various variants of CEPs encoding genes among ten novel Polish strains and indicates the intraspecific diversity exhibited by L. helveticus. In terms of distribution of CEPs genes, four different genetic profiles were found among the microorganisms analyzed. Furthermore, the strains exhibited also various levels of proteolytic activity. Molecular analysis revealed that prtH3 is the most abundant CEPs-encoding gene among the strains investigated. The results indicate also that ecological niche and environmental conditions might affect proteolytic properties of L. helveticus strains. The greatest variety in terms of quantity of the detected CEP encoding genes was noticed in L. helveticus 141, T105 and T104 strains. In these strains, the combination of three nucleotide gene sequences (prtH/prtH2/prtH3) was identified. Interestingly, T104 and T105 exhibited the highest proteolytic activity and also the fastest dynamic of milk acidification among the tested strains of L. helveticus.