Retinoic acid alters metalloproteinase action in red deer antler stem cells.

Metalloproteinases (MMP)s regulate developmental processes, control angiogenesis and wound healing, participate in the formation of immune receptors, and are expressed in stem cells. Retinoic acid (RA) is a potential modulator of these proteinases. The aim was to determine (1) MMPs' action in antler stem cells (ASCs) before and after differentiation into adipo-, osteo-, and chondrocytes and (2) the effect of RA on modifying MMP action in ASCs. Antler tissue from pedicle was collected approximately 40 days after antler casting, post mortem from healthy breeding five year old males (N = 7). The cells were isolated from the pedicle layer of periosteum after skin separation and cultured. The pluripotency of the ASCs was evaluated by mRNA expression for NANOG, SOX2, and OCT4. ASCs were stimulated with RA (100nM) and differentiated for 14 days. The MMP (1-3) and TIMP(1-3) (tissue inhibitor of MMPs) mRNA expression was determined in the ASCs, their concentrations in the ASCs and the medium after RA stimulation as well as profiles of mRNA expression for MMPs: 1-3 and TIMPs: 1-3 during differentiation of ASC to osteocytes, adipocytes and chondrocytes. RA increased MMP-3 and TIMP-3 mRNA expression and output (P < 0.05) and not influenced on MMP-1 and TIMP-1 mRNA expression and output in ASC (P > 0.05). Depending on differentiation of ASC to osteocytes, adipocytes or chondrocytes, MMPs`and TIMPs`expression profile fluctuates for all studied proteases and its inhibitors. The studies demand continuation considering the role of proteases in stem cells physiology and differentiation. The results may be relevant for the study of cellular processes during the cancerogenesis of tumor stem cells.

Use of α-Lactalbumin and Caseinoglycomacropeptide as Biopeptide Precursors and as Functional Additives in Milk Beverages Fermented by L. helveticus.

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 hardness (0.416 ± 0.05 N) were recorded for beverages fermented by DSMZ containing the addition of CGMP, while the lowest value of this parameter (0.186 ± 0.06 N) was noted for products containing α-la and fermented by B734. Moreover, CGMP-containing fermented products were characterized by a generally higher value of the proteolysis index (PI) than analogous variants containing α-la. The use of analyzed strains and the selected protein preparations has a positive effect on the texture of fermented milk beverages and might contribute to an increase in the health-promoting potential of such products.

Fatty Acid Profile and Antioxidative Properties of Peptides Isolated from Fermented Lamb Loin Treated with Fermented Milk.

This study evaluated the impact of fermented milk maceration on fermented lamb loin without nitrate to obtain peptides with high activity against oxidative changes (ABTS, DPPH, reducing power) as well as a favorable fatty acid profile, including CLA content. Additionally, an attempt was made to evaluate the influence of the lamb breed on the assessed properties. Raw loins (m. Longissimus dorsi) obtained from sheep of three polish breeds-Wrzosówka, Uhruska, and Swiniarka-and fermented products were tested. The fermented loins obtained after 14 days of processing were characterized by pH and water activity values in the ranges, respectively, 4.76-5.12 and 0.902-0.915. The maceration of meat in a fermented milk has caused greater acidification of the meat during fermentation. Statistical analysis indicated that treatment was the factor with significant effect on peptide content; no effect of animal breed was found. The peptide content isolated from raw meat ranged from 2.90 to 4.31 mg g-1 of sample, while in fermented meat products it was significant higher (11.59-16.37 mg g-1 of product). The antioxidant properties of peptides were positively correlated with peptides content. The maceration in fermented milk resulted in a statistically significant increase of ABTS value in case of fermented lamb loin of Swiniarka breed. The raw meat and fermented meat products form the Swiniarka lamb breed were characterized by the highest content of the total CLA isomers. The main CLA isomer found was cis9-trans11 (rumenic acid), followed by cis9-cis11, trans9-trans11, and trans10-cis12. The rumenic acid content was higher than, respectively, 87% and 80-88% of total CLA isomers in case of raw meat and fermented lamb loins of three breeds.

Bioactive Compounds in Fermented Sausages Prepared from Beef and Fallow Deer Meat with Acid Whey Addition.

The present study examined the effect of the type of meat (beef and fallow deer) and the addition of freeze-dried acid whey on nutritional values and the content of bioactive compounds (peptides, L-carnitine, glutathione, and conjugated linoleic acid (CLA)) in uncured fermented sausages. The antioxidant properties of isolated peptides (ABTS, DPPH radical scavenging activity, and ferric-reducing antioxidant power) were also evaluated. The results showed that fallow deer sausages had higher peptide content than beef products. The addition of acid whey caused a decrease in the content of peptides, especially in fallow deer sausages. The glutathione content in beef sausages (22.91-25.28 mg 100 g-1 of sausage) was quite higher than that of fallow deer sausages (10.04-11.59 mg 100 g-1 of sausage). The obtained results showed a significantly higher content of CLA in beef sausages than in products from fallow deer meat. In conclusion, products prepared from fallow deer meat have generally higher nutritional value because of the content of peptides, their antioxidant properties, and the content of L-carnitine, while beef products have higher levels of CLA and glutathione.

Comparison of the effect of freeze-dried acid whey on physicochemical properties of organic fermented sausages made from beef and fallow deer meat.

The objective of this study was to compare the effect of freeze-dried acid whey on physicochemical properties and microbial changes of organic fermented sausages made from beef and fallow deer meat. Five formulations of sausages from each species were made. The results show that processing time and species of meat were the high significant factor on tested parameters. Variants and interactions between main factors influenced at different levels of significance on some tested attributes. At the end of processing fallow deer sausages were characterised by the lower pH (4.79 ± 0.01-4.90 ± 0.02 for fallow deer and 5.04 ± 0.00-5.25 ± 0.03 for beef sausages) and the content of 2-thiobarbituric acid reactive substances (1.54 ± 0.09-2.81 ± 0.23 and 1.64 ± 0.15-5.06 ± 0.25 respectively) than sausages made from beef meat. In conclusion, the addition of freeze-dried acid whey in varying amounts did not significantly affect the physicochemical characteristics of sausages from both fallow deer and beef. However, further research is needed to compare the effect of acid whey on the nutritional values of raw fermented sausages from fallow deer and beef.

Nitrates/Nitrites in Food-Risk for Nitrosative Stress and Benefits.

In the context of impact on human health, nitrite/nitrate and related nitrogen species such as nitric oxide (NO) are a matter of increasing scientific controversy. An increase in the content of reactive nitrogen species may result in nitrosative stress-a deleterious process, which can be an important mediator of damage to cell structures, including lipids, membranes, proteins and DNA. Nitrates and nitrites are widespread in the environment and occur naturally in foods of plant origin as a part of the nitrogen cycle. Additionally, these compounds are used as additives to improve food quality and protect against microbial contamination and chemical changes. Some vegetables such as raw spinach, beets, celery and lettuce are considered to contain high concentrations of nitrates. Due to the high consumption of vegetables, they have been identified as the primary source of nitrates in the human diet. Processed meats are another source of nitrites in our diet because the meat industry uses nitrates/nitrites as additives in the meat curing process. Although the vast majority of consumed nitrates and nitrites come from natural vegetables and fruits rather than food additives, there is currently a great deal of consumer pressure for the production of meat products free of or with reduced quantities of these compounds. This is because, for years, the cancer risks of nitrates/nitrites have been considered, since they potentially convert into the nitrosamines that have carcinogenic effects. This has resulted in the development and rapid expansion of meat products processed with plant-derived nitrates as nitrite alternatives in meat products. On the other hand, recently, these two ions have been discussed as essential nutrients which allow nitric oxide production and thus help cardiovascular health. Thus, this manuscript reviews the main sources of dietary exposure to nitrates and nitrites, metabolism of nitrites/nitrates, and health concerns related to dietary nitrites/nitrates, with particular emphasis on the effect on nitrosative stress, the role of nitrites/nitrates in meat products and alternatives to these additives used in meat products.

Comparison of selected parameters related to food safety of fallow deer and beef uncured fermented sausages with freeze-dried acid whey addition.

This study determines the possibility of using freeze-dried acid whey as an alternative to nitrate/nitrite in fermented sausages made from fallow deer meat. The study compared the parameters related to food safety as well as the content of biogenic amines (BAs) in the sausages made from beef meat and fallow deer meat. The results showed slight differences in the physicochemical parameters between these two types of sausages. Stuffings as well as sausages made from fallow deer meat had a significantly (P ≤ .05) higher content of lactic acid bacteria than the beef variants. In addition, depending on the type of meat and additives used, differences were noted in the tested BAs and total BAs. In the case of fallow deer stuffings worse results were observed for food safety-related parameters. Addition of acid whey had a similar effect on the tested parameters as nitrate/nitrite, besides limiting the formation of BAs.

Influence of freeze-dried acid whey addition on biogenic amines formation in a beef and deer dry fermented sausages without added nitrite.

OBJECTIVE: Aim of this study was to evaluate the influence of freeze-dried acid whey addition and the use a game meat (fallow deer) on a microbial content and the biogenic amines formation in dry fermented sausages. METHODS: The experiment involved dry fermented sausages made in two variants from beef and from fallow deer. Each variant was divided into five groups: control (with a curing mixture), reference (with a sea salt), sample with a liquid acid whey and two samples with the addition of reconstituted freeze-dried acid whey in different concentrations. Changes in lactic acid bacteria (LAB), Enterobacteriaceae content and biogenic amines content were determined. RESULTS: The microbial content changes suggest that addition of acid whey slightly affected lactic acid bacteria content in comparison with the control and reference sample, but the addition of freeze-dried acid whey resulted in a reduction of Enterobacteriaceae content in the sausages from fallow deer or a similar level in the beef sausages compared with the control and reference sample. Both changes in lactic acid bacteria and Enterobacteriaceae content were more evident in case of sausages made from fallow deer. Addition of acid whey (liquid and a higher amount of freeze-dried) and use of fallow deer meat to produce the sausages resulted in a significant reduction of total biogenic amines content. CONCLUSION: The addition of acid whey (liquid and higher amount of freeze-dried) resulted in a significant reduction of total biogenic amines content in dry fermented sausages made from fallow deer meat.

Impact of Sodium Nitrite Reduction on Lipid Oxidation and Antioxidant Properties of Cooked Meat Products.

Oxidation processes are responsible for reduction of the sensory and nutritional quality of meat and meat products, thus affecting consumer acceptance. The use of sodium nitrite in meat processing is an important factor limiting these changes. Therefore, eliminating this substance from the recipe of meat products to increase their nutritional value is not an easy challenge. The aim of this study was to determine the effect of sodium nitrite reduction on the lipid oxidation (peroxide value, thiobarbituric acid reactive substances), and color parameters (CIE L*a*b*, total heme pigment and heme iron, nitrosylmyoglobin) in cooked meat products during 15 days of vacuum storage. The antioxidant properties of products and isolated peptides (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric-reducing antioxidant power) were also evaluated. Experimental material included four different sample groups of cooked meat products produced with various percentages of sodium nitrite (0, 50, 100, and 150 mg kg-1). It was shown that the sodium nitrite dose had no statistically significant effect on lightness (L*) and redness (a*) values, as well as nitrosylmyoglobin content. Along with decreasing the share of sodium nitrite in the samples, the thiobarbituric acid reactive substances (TBARS) value increased from 0.43 mg kg-1 for samples with 150 mg kg-1 at day 0 to 3.14 mg kg-1 for samples without nitrite at day 15. The total ABTS scavenging capacity of the cooked meat samples was in the range 2.48 to 4.31 eqv. mM Trolox per g of product throughout the entire storage period. During storage, the ferric-reducing antioxidant power of samples with nitrite increased from 0.25 to 0.38 eqv. mg/mL ascorbic acid per g of product. In conclusion, reduction of nitrite to the level of 50 mg kg-1 seemed to be comparable with the traditional use of nitrite in meat products in terms of the physicochemical properties and properties related to lipid oxidation, as well as total antioxidant capacity and peptide antioxidant capacity.

Meat and meat products ­ analysis of the most common threats in the years 2011-2015 in Rapid Alert System for Food and Feed (RASFF)

Background: The key tool used in the European Union in order to eliminate the risks associated with the consumption of potentially hazardous food is RASFF - Rapid Alert System for Food and Feed Safety. The RASFF was established to increase accountability and strengthening cooperation between states of the European Union in the field of food safety control. Objective: The aim of this study was to explore the trends and temporal and spatial distribution of notifications on food safety hazards between January 2011 and December 2015 with a special emphasis on meat and meat products on the basis of notification from RASFF. Material and methods: The study analyzed notifications on the annual reports of the RASFF published by the European Commission and requests added to the portal RASFF in the period 01.01.2011 - 31.12.2015 on the category of "meat and meat products (other than poultry) and "poultry meat and poultry meat products". Analysis included detailed information on each notification, such as the classification and date, hazard category, notifying country, country origin. Results: The most common classifications of notification were 'alert' and 'border rejection'. Generally, basis of this notifications were 'company's own check' and 'official control on the market'. Pathogenic microorganisms were the most often hazard of category in which the higher number of notifications concerned with Salmonella spp. Conclusion: Alert notification which is the most dangerous for consumers were the most common type of classification for notifications on 'meat and meat product' category. The most of notifications in category 'poultry meat and poultry meat products' were the result of border control. Pathogenic microorganisms were the reason for the huge number of notifications in studied product categories. Many of notifications were associated with products which origin countries were outside RASFF member states.