ACTA Scientiarum Polonorum - Technologia Alimentaria News en (c) Wydawnictwo Uniwersytetu przyrodniczego w Poznaniu Meat and fermented meat products as a source of bioactive peptides

Bioactive peptides are short amino acid sequences, that upon release from the parent protein may play different physiological roles, including antioxidant, antihypertensive, antimicrobial, and other bioactivities. They have been identifi ed from a range of foods, including those of animal origin, e.g., milk and muscle sources (with pork, beef, or chicken and various species of fi sh and marine organism). Bioactive peptides are encrypted within the sequence of the parent protein molecule and latent until released and activated by enzymatic proteolysis, e.g. during gastrointestinal digestion or food processing. Bioactive peptides derived from food sources have the potential for incorporation into functional foods and nutraceuticals. The aim of this paper is to present an overview of the muscle-derived bioactive peptides, especially those of fermented meats and the potential benefi ts of these bioactive compounds to human health.

Chosen quality parameters of pork sausage produced without curing mixture

Background. The aim of this study was to determine the infl uence of the dried celeriac juice addition, as a nitrogenous compounds sources, on the quality of the experimental pork sausage.
Material and methods. In the sausages with vegetable preparation addition and in traditionally cured sausages amount of the sodium nitrate (III) and sodium nitrate (V) was determined (in the batter and 24 h after production). Moreover the total number of aerobic bacteria, number of coli forms, anaerobic survived bacteria, coagulase positive staphylococci, Listeria monocytogenes and occurrence of Salmonella in 25 g (according to Polish Standards) was determined during sausages storing (after 2, 14 and 21 days). Also sensory evaluation was carried out (after 2 and 14 days). After 2, 7, 14 and 21 days the amount of drip loss in the package was determined.
Result. In the experimental sausage produced with the addition of vegetable preparation (E0), the content was 2.2 times higher of sodium nitrate (V) while sodium nitrate (III) three times lower, compared to traditionally cured sausages (K). In the E0 sausages faster aerobic microorganisms proliferation was observed. However, in these products, in comparison to the control group (K), no higher contamination with coliform bacteria, anaerobic sporulating bacteria, coagulase positive Staphylococci, Listeria monocytogenes or Salmonella was found. The sensory evaluation (colour in cross-section, fl avour, taste, consistency) showed no statistically significant difference between the experimental sausages.
Conclusions. In the sausages produced with dried celeriac juice addition there was above twice more sodium nitrate (V) and threefold less sodium nitrate (III) in comparison to traditionally cured sausages and faster growth of aerobic bacteria was demonstrated. Sensory quality of ‘cold’ and ‘hot’ sausages without curing salt was worse, but the score number was never lower than 4,1, so the sausages were accepted. In the vacuum packaged sausages produced with the addition of vegetable preparation higher, about 0.3–0.4 percent score, drip loss was found.

Applicability of bacterial growth models in spreadable processed cheese

Background. Food spoilage is a process in which the quality parameters decrease and products are no longer edible. This is a cumulative effect of bacteria growth and their metabolite production, which is a factor limiting shelf life. Thus, the aim of the study was to evaluate whether microbiological growth models for total viable count (TVC) and Clostridium strain bacteria are reliable tools for prediction of microbiological changes in spreadable processed cheese.
Material and methods. Investigations were conducted for two types of bacteria: TVC and Clostridium in following temperature: 8°C, 20°C and 30°C. A total number of aerobic bacteria was determined based on standard PN-EN ISO 4833:2004 and Clostridium was detected by using microbiological procedure for sulphite-reducing anaerobic spore-bacteria with a selective nourishment. During the analysis nonlinear regression and Baranyi and Roberts primary model were used.
Results. For temperatures 20°C and 30°C, Baranyi and Roberts model, for total viable count showed determination coeffi cient of 70%. The models prepared for Clostridium, in these temperatures, showed much lower R2, respectively 25% and 30%. At the abovementioned temperatures also the expiration of product shelf life was much shorter and amounted 70 days at 20°C and 7 days at 30°C. For both types of bacteria incubated at 8°C the numbers of bacteria decrease until the expiration of product shelf life.
Conclusions. Models used in the analyses, Baranyi and Roberts and nonlinear regression, poorly matched the experimental data, hence they are not reliable tools. Nevertheless, they gave information about dynamic of microbiological changes in spreadable processed cheese.

Effect of complexation conditions on microcapsulation of Lactobacillus acidophilus in xanthan-chitosan polyelectrolyte complex gels

Background. Lactobacillus acidophilus has become increasingly popular because of their beneficial effects on health of their host, and are called proboscis. In order to exert benefi cial effects for probiotics, they must be able to tolerate the acidic conditions of the stomach environment and the bile in the small intestine. Microencapsulated form has received reasonable attention, since it can protect probiotic organisms against an unfavourable environment, and to allow their release in a viable and metabolically active state in the intestine. The aim of this study was to investigate some factores, such as chitosan solution pH and concentration, xanthan concentration, cell suspension-xanthan ratio, mixed bacteria glue liquid-chitosan ratio, which impacted the process of microencapsulation of L. acidophilus.
Material and methods. In this study, L. acidophilus was immobilized with xanthan⁄chitosan gel using extrusion method. The viable counts and encapsulation yield of L. acidophilus encapsulated in different chitosan solution pH (4.5, 5, 5.5 and 6), in different chitosan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different xanthan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different cell suspension-xanthan ratios (1:5, 1:10, 1:15 and 1:20), in different mixed bacteria glue liquid-chitosan ratios (1:3, 1:4, 1:5 and 1:6), have been investigated by single factor experiment method.
Results. The optimum conditions of microencapsulated L. acidophilus have been observed. The optimum chitosan solution pH for L. acidophilus was 5.5; the optimum chitosan concentration was 0.9%; the optimum xanthan concentration was 0.7%; the optimum cell suspension-xanthan ratio was 1:10; the optimum mixed bacteria glue liquid-chitosan ratio was 1:3.
Conclusions. These results will be helpful to further optimize the process of L. acidophilus microencapsulation, and provide reference for obtaining higher viable counts and entrapped yield of L. acidophilus microcapsules.

Physicochemical and antimicrobial properties of copaiba oil: implications on product quality control

Background. The copaiba oil is a common natural product used in cosmetic industry and as a nutraceutical product. However, lack of quality control and scarce knowledge about its antimicrobial activity is a point of concern. The proposal of this study was to investigate the physicochemical properties and the antimicrobial activity of five commercial brands of copaiba oil.
Material and methods. Acidity and ester index, refractory index, solubility in alcohol, and thin layer chromatography were performed to verify the physicochemical properties of five commercial copaiba oils sold in local pharmacies. Ultra performance liquid chromatography coupled with diode-array detection and electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-DAD/ESI-Q-TOF-MS) was used to investigate diterpene acids while the volatile compounds were analysed by gas chromatography-mass spectrometry (GC-MS). Antibacterial and antifungal activities were also evaluated by agar diffusion technique; and minimal inhibitory concentration and maximal bactericidal concentration were defi ned for each sample and bacteria.
Results. The physical-chemical analysis revealed heterogeneity between all samples analysed. The A1 sample showed characteristics of copaiba oil and was mainly composed by hydrocarbon sesquiterpenes (29.95% β;-bisabolene, 25.65% Z-α-bergamotene and 10.27% β;-cariophyllene). Among diterpene acids, the UPLCDAD/ESI-Q-TOF-MS data are compatible with presence of copalic and/or kolavenic acid (m/z 305 [M + H]+). Candida albicans was sensitive to almost all samples at high concentration and Saccaromyces. Cerevisiae showed sensitivity to A1 sample at 100 mg/mL. Although variable, all samples showed antibacterial activity. Significant activity was seen for A3 (19.0 ±0 and 15.6 ±0.5 mm), A4 (16.6 ±0.5 and 15.6 ±0 mm), and A5 (17.1 ±0 and 17.1 ±0 mm) on Staphylococcus saprophyticus and S. aureus, respectively. All samples were active against Klebsiella pneumoniae showing ≥15 mm diameter halo inhibition; and only A2 was active against Eschirichia coli. Phytopatogens tested revealed resistance of Ralstonia solanacearum CGH12 to all samples and susceptibility of Xcv 112 strain of Xanthomonas campestris pv campestris to almost all samples. MIC and MMC showed bacteriostatic effect against clinical interest bacteria and bactericidal effect against phytopatogens.
Conclusion. The results from physicochemical analysis reinforce the fact that it is imperative to include simple conventional methods in the analysis of oil products. The analysis of copaiba oil gives safe products and purity which ensure products with quality. Also, since copaiba oil is an over-the-counter product the results indicate that pharmacosurveillance must be improved by the governmental regulation agency to avoid microorganism resistance selection and to achieve better international quality products.

Optimization of the medium for Lactobacillus acidophilus by Plackett-Burman and steepest ascent experiment

Background. Lactobacillus acidophilus not only improves the intestinal flora balance but also inhabits the growth of undesirable microorganisms in intestine, which is benefit to the health of humans and animals. Plackett-Burman and steepest ascent experiment are the rapid and concise ways of screening the main effective factors. This study is aimed to select the main influence factors and optimize the medium for Lactobacillus acidophilus by Plackett-Burman experiment and steepest ascent experiment.
Material and methods. The ideal carbon source was screened among glucose, maltose, lactose and whey powder, and the ideal nitrogen source was screened among casein hydrolysate, peptone, yeast extract powder, fish meal, carbamide, ammonium sulfate and sodium nitrate by single factor experiment. Plackett-Burman and steepest ascent experiment were applied to screen the main effective factors of Lactobacillus acidophilus among peptone, beef extract, yeast extract powder, glucose, K2HPO4, C6H14O7N2, CH3COONa, MgSO4 and Tween-80.
Result. The results indicated that glucose (p = 0.01510) as negative factor and K2HPO4 (p = 0.02017) as positive effect were the significant growth factors of Lactobacillus acidophilus, CH3COONa (p = 0.09273) as positive effect was an important factor, and the optimized medium was as follows: glucose – 21 g/L, K2HPO4 – 3.5 g/L, CH3COONa – 6.5 g/L, peptone – 10 g/L, beef extract – 8 g/L, yeast extract powder – 8 g/L, C6H14O7N2 – 2 g/L, MgSO4 – 0.2 g/L and Tween-80 – 1 mL/L when the maximum viable count could achieve 2.72·109 cfu/mL.
Discussion. The experimental model is reliable and the experimental results are of good stability. Variance analysis is performed to determine the adequacy and significance of the linear model. Thus, Plackett-Burman and steepest ascent experiment improve the veracity of optimization the medium for Lactobacillus acidophilus compared with the previous research.

Effect of germination time on proximate analysis, bioactive compounds and antioxidant activity of lentil (Lens culinaris Medik.) sprouts

Background. The lentil plant, Lens culinaris L., is a member of the Leguminoceae family and constitutes one of the most important traditional dietary components. The purpose of the current study was to investigate the effects of sprouting for 3, 4, 5 and 6 days on proximate, bioactive compounds and antioxidative characteristics of lentil (Lens culinaris) sprouts.
Material and methods. Lentil seeds were soaked in distilled water (1:10, w/v) for 12 h at room temperature (~25°C), then kept between thick layers of cotton cloth and allowed to germinate in the dark for 3, 4, 5 and 6 days. The nutritional composition, protein solubility, free amino acids, antinutritional factors, bioactive compounds and antioxidant activity of raw and germinated samples were determined using standard official procedures.
Results. Sprouting process caused significant (P ≤ 0.05) increases in moisture, protein, ash, crude fiber, protein solubility, free amino acids, total, reducing and nonreducing sugars. However, oil content, antinutritional factors (tannins and phytic acid) significantly (P ≤ 0.05) decreased. Results indicated that total essential amino acids of lentil seeds protein formed 38.10% of the total amino acid content. Sulfur-containing amino acids were the first limiting amino acid, while threonine was the second limiting amino acid in raw and germinated lentil seeds. Sprouting process has a positive effect on the essential amino acid contents and protein efficiency ratio (PER) of lentil sprouts. Phenolics content increased from 1341.13 mg/100 g DW in raw lentil seeds to 1411.50, 1463.00, 1630.20 and 1510.10 in those samples germinated for 3, 4, 5 and 6 days, respectively. Sprouted seeds had higher DPPH radical scavenging and reducing power activities.
Conclusions. Based on these results, sprouting process is recommended to increase nutritive value, and antioxidant activity of lentil seeds.

Lactobacillus strains belonging to Casei group display various adherence to enterocytes and mucus

Background. The ability of lactobacilli to adhere to the surface of the intestine is an important functional characteristic which can largely determine the effective colonization of the intestinal tract by probiotics. The following study compares the adhesion efficiency of the twenty strains of Lactobacillus genus belonging to Casei group to the Caco-2 cells and gastrointestinal mucus.
Material and methods. Twenty isolates of lactobacilli belonging to Casei group were tested. The ability of bacterial cells to adhere to mucus was examined using adhesion assay to gastrointestinal mucus. Obtained results were compared with adhesion efficiency to Caco-2 cells. Phylogenetic relationship between isolates was analysed by rep-PCR.
Results. The results showed large differences in adhesion efficiency between strains, as well as differences in the efficiency of adhesion to the intestinal epithelial cells and mucus. Group similarity highlighted by a rep-PCR technique does not correspond with groups of similarity in terms of the characteristics of the ability to adhere to mucus or the epithelial cells of intestinal tract.
Conclusions. Strains having a high adhesion efficiency to enterocytes do not always show a high adhesion efficiency to the mucus. This may indicate the presence of different and multiple factors responsible for adhesion efficiency of Lactobacillus group Casei strains to epithelial cells and mucus.

Dietary gender differences in terms of the risk of atherogenesis in Poland

Introduction. Diet plays an important role in prevention of atherosclerosis. The objective of the study was to assess differences in the dietary intake and nutritional status in women and men in terms of atherogenesis risk.
Material and methods. The study involved 41 women and 49 men aged 40+. The nutrient intake was assessed using 7-day dietary records. The nutritional status was estimated on the basis of antropometric measurements and biochemical blood parameters. The differences between diets and the nutritional status depending on sex was evaluated by oneway analysis of variance. The dependencies between the nutritional status and the diet factors were assessed using multiple regression.
Results and discussion. It was found that a signifi cant proportion of the women and men were overweight or obese, had lipid disorders and impaired fasting glucose. Diets of women and men were poorly balanced. A signifi cant correlation between the level of energy from protein, as well as the energy supply and the LDL cholesterol concetration was found in the women. A positive correlation between energy from protein as well as total energy in the diet and body weight, was observed in women and men. Moreover, protein intake was positively correlated with BMI and waist circumference among the men. In the men, the level of serum triglycerides correlated with an increase in dietary cholesterol and a decrease in energy value.
Conclusion. This study indicates that an inadequate diet among both men and women represents a real health danger of developing atherosclerotic plaque.

Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes

Background. A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the infl uence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in Wistar rats.
Material and methods. 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the fi rst and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA) in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits.
Results. Intragastric administration of zinc asparaginate signifi cantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats’ organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity.
Conclusion. The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.