Changes in physicochemical, textural, and sensorial properties of pork meatballs made with the addition of hemp oil during storage.

This research aimed to evaluate the quality characteristics of cooked and vacuum-packed meatballs reformulated with cold-pressed hempseed oil as a partial pork substitute (0.8%, 2.5%, 4.2%, and 7.5%) during 12 days of storage. The water activity, cooking, and storage losses increased with a higher content of hemp oil (P < 0.05). The total saturated fatty acids were reduced by 37.6%, whereas the polyunsaturated fatty acids content improved by 96.1%. Hemp oil addition decreased protein and lipid oxidation during the storage period (P < 0.05). The inhibition effect on carbonyl content reached 34.9% and on TBARS values reached 17.5%. Sensory analysis revealed no significant changes to the texture, odour, and taste attributes over 12 days of storage in vacuum packaging. The results indicate that cold-pressed hemp oil can be an alternative ingredient for the production of meat products with improved nutritional value, particularly by enriching them with n-3 α-linolenic fatty acid.

Protein Fractions from Flaxseed: The Effect of Subsequent Extractions on Composition and Antioxidant Capacity.

Flaxseed proteins exhibit functionalities interesting for the food industry, including antioxidant capacity. Antioxidant activity depends on the protein composition and the presence of phenolic compounds extracted with them from the matrix. The research focused on the effect of subsequent protein extractions (water, salt and alkaline) of flaxseed meals (of three cultivars) on the protein fraction composition and its relations to antioxidant capacity. The protein and phenolic profiles and antioxidant functionalities (in antiradical ORAC and emulsion assays) were analysed. Spectroscopic characteristics of the fractions (fluorometric and FT-IR analysis) were also included. Our study has shown the effect of fractionation on the share of proteins at MW from 56-38 kDa (globulin-like) and <15 kDa (albumin-like) in the protein profiles. The highest globulin share was in the alkaline-extracted fractions (AEF) and albumin in the salt-extracted (SEF) ones. SDG (secoisolariciresinol diglucosides) and phenolic acids (p-coumaric and ferulic) were extracted with flaxseed proteins. Their contents were fraction-dependent and the highest in AEF. The concentration of phenolics in AEF corresponded with the highest antiradical capacity (ORAC) compared with the other fractions. However, the SEF showed a higher ability to inhibit oxidation in emulsions than AEF, which could be associated with the higher content of the low MW proteins.

The Effect of Hemp Cake (Cannabis sativa L.) on the Characteristics of Meatballs Stored in Refrigerated Conditions.

Hemp cake, a by-product of cold pressing oil from hemp seeds, is a nutritious ingredient that could be used for the production of new or reformulated meat products. The aim of this study was to determine the influence of inclusion of 0.9%, 2.6%, 4.2%, and 7.4% (w/w) hemp cake (Cannabis sativa L.) on the physicochemical and textural properties, oxidation, and sensory acceptance of cooked and vacuum-packed meatballs during refrigerated storage. The addition of 7.4% hemp cake enhanced the amount of dry matter and reduced the content of water. Lightness (L*) and redness (a*) values reduced significantly with higher levels of hemp supplementation. Regardless of the amount of hemp additive, pH, color parameters did not differ significantly during the 12 days of storage. Hemp cake significantly decreased protein and lipid oxidation: the inhibitory effect of adding 7.4% hemp cake on protein carbonyl group formation and TBARS values reached 11.16% and 36.5%, respectively, after 10 days of storage. Sensory analysis revealed that meatballs prepared with 0.9% and 2.6% hemp cake gained higher overall scores. The results indicate that hemp cake, a material considered mainly as waste, may be destined for food purposes and be an alternative ingredient for the production of sustainable meat products.

Selected Quality Attributes of Freshwater Mussel Powder as a Promising Ingredient for Pet Food.

The aim of this study was to describe the quality attributes of a freeze-dried preparation obtained from freshwater mussel Sinanodonta woodiana (SW) soft tissue in respect to its potential as a novel pet food ingredient. After ecotoxicological testing of the raw material with MARA (Microbial Assay for Risk Assessment), the basic physico-chemical properties of the powder, such as approximate composition, bulk density, color parameters, water activity, electrophoretic analysis (SDS-PAGE), solubility, gelling and emulsifying capacity, were analyzed. The powder with a water activity of 0.43 offers a toxically safe preparation that contains over 34% protein/100 g of dry matter (DM). The SDS-PAGE profile showed twelve protein bands with a molecular weight (MW) ranging from >250 to 10 kDa. Taurine content has been estimated at an essential amount above 150 mg/100 g of DM. The powder possessed desirable emulsifying properties with 230 mL per 1 g and demonstrated the ability to form a firmer gel with a strength of 152.9 g at a temperature above 80 °C with at least 10% protein content. The L*, a*, and b* values characterizing powder color were found to be 69.49, 16.33, and 3.86, respectively. The SW mussel powder seems to be a promising ingredient that can be added with other binding or gelling agents in order to improve both the taste and acceptance of the final pet food products.

The Effect of Roasting on the Protein Profile and Antiradical Capacity of Flaxseed Meal.

Roasting is more and more often used as a pre-treatment of flaxseeds. However, the process can influence flaxseed proteins that may be crucial for their properties. The aim of this research was to study changes in the electrophoretic protein profile (SDS-PAGE) and the antiradical capacity of flaxseed meals after roasting. The roasting temperature (160, 180, and 200 °C) and flaxseed cultivars (golden and brown seed) were factors including in the study. The free (F-MRP) and bound-to-protein (B-MRP) Maillard reaction products were also analyzed. The most significant changes in the SDS-PAGE protein profiles of roasted seeds of each of the tested flax cultivars were observed for the 13 kDa protein fraction (decrease) and for the 19 kDa and 17 kDa fractions (increase). The research revealed a significant correlation between the roasting temperature and B-MRP content, and changes in the percentage share of those three protein fractions. The antiradical capacity of roasted flaxseeds decreased, as compared with untreated seeds. After roasting at 200 °C the antiradical capacity of flaxseeds improved slightly, probably due to the MRP formation, but it was still significantly lower than that of the raw seeds. The research provides novel information about key protein fractions that seem to be important changing during heat treatment.

Effects of Effective Microorganisms on Meat Quality, Microstructure of the Longissimus Lumborum Muscle, and Electrophoretic Protein Separation in Pigs Fed on Different Diets.

The aim of the study was to determine how effective microorganisms influence meat quality, the microstructure of the longissimus lumborum muscle, and electrophoretic protein separation. The study group consisted of 150 piglets divided into three feeding groups: C, E1, and E2. The feeding groups included C-a standard fodder blend with a full share of post-extracted soya meal; E1-a 50%/50% mix of pea and lupine/soya bean in phase I of fattening and a 75%/25% mix of pea and lupine/soya bean in phase II of fattening; and E2-a 50%/50% mix of pea and lupine/soya bean in phase I of fattening and in 100% pea and lupine in phase II of fattening. The experimental factor was the addition of the EM Carbon Bokashi probiotic to the diet (C + EM, E1 + EM, E2 + EM). Influence of the feeding system on the following parameters was also estimated. After slaughter, the meat quality, LL muscle microstructure, and electrophoretic protein separation were assessed. In the C + EM group, a lower water-holding capacity was demonstrated. Meat from pigs fed the effective microorganism additive was much harder in the E1+EM group compared to meat from pigs from the E1 group. A beneficial effect of effective microorganism was found in the E2 + EM group, where less thermal leakage from the meat was demonstrated. A beneficial effect of the feeding system on thermal leakage and loin eye area in the E2 + EM group was demonstrated. In the C + EM group, a lower total number of muscle fibers was demonstrated. The addition of effective microorganism caused an increase in the diameter of fast twitch fibers in the E1 + EM group. In the same group of pigs, effective microorganisms caused a lower proportion of fiber fission. This nutritional variant appears to be the most appropriate for proteins as well, because it led to the most favorable percentage of individual proteins after effective microorganisms supplementation in the longissimus lumborum muscle.

LC⁻Q⁻TOF⁻MS/MS Identification of Specific Non-Meat Proteins and Peptides in Beef Burgers.

Beef burgers are a popular food choice, due to their taste and convenience. The extensive range of beef burgers with different flavours currently offered on the market is adding to their growing consumption. This study detected and identified specific non-meat proteins and peptide markers originating from functional preparations, i.e., powdered mixes of protein additives and spices, used as meat substitutes in the production of ready-to-cook beef burgers. Twenty-eight soy proteins, including isoforms (nine milk-, three pea- and one beetroot-specific protein) were found concurrently with a set of peptide markers unique to soy glycinin and ß-conglycinin, pea vicilin and provicilin, milk αS1-casein, ß-lactoglobulin, as well as beetroot elongation factor 2. Soy and beetroot proteins and peptides were observed in all burgers containing additives. Milk and pea proteins were included in powdered mixes but were not detected in burgers, indicating that their content was below the limit of detection. The study demonstrates that the proposed method can be implemented to analyse protein additives in cooked burgers; however, the presence of low amounts of additives, below 1⁻2%, should be further confirmed by using a more sensitive triple quadrupole instrument.

Changes in oxidative stability and protein profile of flaxseeds resulting from thermal pre-treatment.

BACKGROUND: The oxidative stability of oilseeds is crucial for their technological/nutritional quality and shelf life. This research aimed to evaluate the effect of thermal pre-treatment (steaming and roasting under various time/temperature conditions) on flaxseed oil and protein stability. The monitoring of changes in oil oxidation in situ and protein profiles (SDS-PAGE) and analysis of the antiradical activity of ethanolic and aqueous fractions were included in the study. RESULTS: Flaxseed stability during storage was considerably affected by thermal pre-treatment conditions. Dynamics of oil oxidation was accelerated at 160 °C and 180 °C but slowed at 200 °C. Influence of pre-treatment conditions on the antiradical activity of the aqueous fraction was clearly observed and no effect concerning the ethanolic fraction was found. The most significant changes in protein profile of 200 °C-roasted flaxseed were found with the observed disappearance of 19 kDa protein. A treatment-dependent decrease in the 13 kDa protein was also detected. Based on the aqueous extract protein profiles, roasting conditions were found to be crucial for protein extractability. CONCLUSIONS: The study has broadened knowledge of the consequences of flaxseed thermal treatment. The deterioration of flaxseed oil oxidative stability is shown. The changes of 19 and 13 kDa proteins suggest their sensitivity to thermally induced aggregation and/or cross-link. © 2018 Society of Chemical Industry.

Impact of polymorphism of the regulatory subunit of the µ-calpain (CAPN1S) on the proteolysis process and meat tenderness of young cattle.

The objective of this study was to estimate the impact of the polymorphism of µ-calpain (CAPN1S) gene on protein changes of the cattle muscle tissue and its tenderness during 10-day cold storage. The analysis was performed on the longest dorsal and lumbar muscles collected from 76 bulls 6 to 12 months of age. Polymorphism identification of the above-mentioned gene was conducted using the PCR-RFLP technique. Its effect on the course of the proteolysis process was assessed by monitoring changes in proportions of tissue proteins during 10-day process of meat ageing. Special attention was focused on changes in native titin (T1) share and products of its degradation (proteins of molecular weight (m.w.) of 2400 and 200 kDa), α-actinin and protein of 37 kDa as well as myosin heavy chains (MHC). In the case of the last proteins, their polymorphism was evaluated as well. Meat tenderness was estimated measuring the value of shear force and sensorially. The highest tenderness was ascertained for the heterozygote. Its improvement was associated with a significant decrease in proportions of proteins of molecular weight of approximately 37 kDa accompanied by an increase of those with 200 kDa molecular weight. Muscles derived from cattle of CT genotype were characterised by the highest proportions of type 2a MHC isoform. Value differences between proportions determined for the heterozygote and CC and TT homozygotes of the CAPN1S gene were statistically significant. Therefore, it can be presumed that the process of meat tenderisation was especially connected with MHC polymorphism.

Thermal properties of titin from porcine and bovine muscles.

The thermal properties of titin isolated from porcine and bovine longissimus muscles were investigated by differential scanning calorimetry in the temperature range from 20 to 100 °C. A single peak with average maximum temperatures of 75.6 and 78.4 °C characterized porcine and bovine titin denaturation, respectively. The peaks were much broader than those from the other major muscle proteins. Titin denaturation enthalpy values (1.6-2.6 J/g) were only about half those of whole meat and also lower than those previously determined for myosin, actin, or collagen. The relatively high titin denaturation temperature suggests that it may be partially responsible for meat toughening when muscle tissue is heated above 60 °C.