An Analysis of Changes in the Physicochemical and Mechanical Properties during the Storage of Smoked and Mould Salamis Made in Poland.

The aim of the study was to analyse changes in the physicochemical, rheological, and textural properties occurring during the storage of industrially produced smoked salami and mould salami. Tests on these cold cuts were conducted on the 2nd, 15th, 30th, and 45th days of storage. There was a significant increase in the pH value of the mould salami from 5.16 on the 2nd day to 5.42 on the 45th day (p < 0.05). There was a downward trend in the Aw of the smoked salami sample from 0.892 on the 2nd day to 0.873 on the 45th day. The Aw in the mould salami sample decreased from 0.889 on the 2nd day to 0.847 on the 15th day and then increased to 0.871 on the 45th day (p < 0.05). In the first two test periods, the smoked salami was characterised by a higher modulus of elasticity value than the non-smoked salami but lower loss tangent and dynamic viscosity values. The hardness of the whole bars, as well as the hardness of the salami pieces, was affected by their storage time and the related water content. The texture test results showed that the smoked salami was more resistant to compressive force than the mould salami, which affected the sensory evaluation and ease of slicing of this type of salami.

Microscopic Droplet Size Analysis (MDSA) of "Five Thieves' Oil" (Olejek Pieciu Zlodziei) Essential Oil after the Nebulization Process.

Nowadays, due to a higher resistance to drugs, antibiotics, and antiviral medicaments, new ways of fighting pathogens are intensively studied. The alternatives for synthesized compositions are natural products, most of which have been known in natural medicine for a long time. One of the best-known and intensively investigated groups are essential oils (EOs) and their compositions. However, it is worth noting that the method of application can play a second crucial part in the effectiveness of the antimicrobial activity. EOs possess various natural compounds which exhibit antimicrobial activity. One of the compositions which is based on the five main ingredients of eucalyptus, cinnamon, clove, rosemary, and lemon is named "five thieves' oil" (Polish name: olejek pieciu zlodziei) (5TO) and is used in natural medicine. In this study, we focused on the droplet size distribution of 5TO during the nebulization process, evaluated by the microscopic droplet size analysis (MDSA) method. Furthermore, viscosity studies, as well as UV-Vis of the 5TO suspensions in medical solvents such as physiological salt and hyaluronic acid, were presented, along with measurements of refractive index, turbidity, pH, contact angle, and surface tension. Additional studies on the biological activity of 5TO solutions were made on the P. aeruginosa strain NFT3. This study opens a way for the possible use of 5TO solutions or emulsion systems for active antimicrobial applications, i.e., for surface spraying.

The Effect of Packaging Methods, Storage Time and the Fortification of Poultry Sausages with Fish Oil and Microencapsulated Fish Oil on Their Rheological and Water-Binding Properties.

The aim of the study was to investigate how liquid fish oil and microencapsulated oil additives influenced the rheological characteristics and the dynamics of water binding in vacuum-packed (VP) and modified-atmosphere-packed (MAP) poultry sausages during 21-day storage. In contrast to the control sample, the sausages enriched with microencapsulated fish oil (MC) were characterised by the greatest ability to accumulate deformation energy. The elastic properties of all sausage variants increased significantly in the subsequent storage periods, whereas the dynamic viscosity of the samples tended to decrease. This phenomenon was confirmed by the gradual reduction of water activity (Aw) in all sausages in the subsequent storage periods. The packaging method influenced the dynamics of water binding in an oil-additive-form-dependent manner. During the storage of the VP and MAP sausages, in samples with the fish oil additive the T1 value tended to increase while the Aw decreased. The T1 value in the MAP MC sample was similar. The FO additive resulted in greater mobility of both proton fractions in the MAP samples than in the VP samples. There were inverse relationships observed in the MC samples. The NMR tests showed that the VP samples with the MC additive were slightly better quality than the other samples.

Whey Proteins as a Potential Co-Surfactant with Aesculus hippocastanum L. as a Stabilizer in Nanoemulsions Derived from Hempseed Oil.

The use of natural surfactants including plant extracts, plant hydrocolloids and proteins in nanoemulsion systems has received commercial interest due to demonstrated safety of use and potential health benefits of plant products. In this study, a whey protein isolate (WPI) from a byproduct of cheese production was used to stabilize a nanoemulsion formulation that contained hempseed oil and the Aesculus hippocastanum L. extract (AHE). A Box-Behnken experimental design was used to set the formulation criteria and the optimal nanoemulsion conditions, used subsequently in follow-up experiments that measured specifically emulsion droplet size distribution, stability tests and visual quality. Regression analysis showed that the concentration of HSO and the interaction between HSO and the WPI were the most significant factors affecting the emulsion polydispersity index and droplet size (nm) (p < 0.05). Rheological tests, Fourier transform infrared spectroscopy (FTIR) analysis and L*a*b* color parameters were also taken to characterize the physicochemical properties of the emulsions. Emulsion systems with a higher concentration of the AHE had a potential metabolic activity up to 84% in a microbiological assay. It can be concluded from our results that the nanoemulsion system described herein is a safe and stable formulation with potential biological activity and health benefits that complement its use in the food industry.

An Analysis of Oxidative Changes and the Fatty Acid Profile in Stored Poultry Sausages with Liquid and Microencapsulated Fish Oil Additives.

This study deals with the fatty acid profile and oxidative changes (TBARS) in vacuum-packed (VP) or modified-atmosphere-packed (MAP) finely-comminuted poultry sausages with liquid fish oil and microencapsulated fish oil (MC) additives. An analysis of omega-3 fatty acids (EPA and DHA) showed that their content in the samples with the fish oil additive decreased from the initial value of 0.22 g∙100 g-1 of the product to 0.18 g∙100 g-1 (MAP) and 0.17 g∙100 g-1 (VP), respectively. After in vitro digestion, the total EPA and DHA content in the sample with microencapsulated oil amounted to 0.17 g∙100 g-1 of the product. The TBARS values showed the VP samples with both forms of the fish oil additive had the lowest values on the first day of storage. Storage of the samples for 21 days caused a slight increase in the degree of lipid oxidation. The research indicated that the forms of the oil additive did not have a negative influence on the sensory features or the physicochemical properties of the sausages. The EPA and DHA levels in samples with liquid fish oil and those with oil microcapsules were sufficient for the sausage producer to declare high content of these fatty acids in accordance with the current EC regulation.

The Influence of Packing Methods and Storage Time of Poultry Sausages with Liquid and Microencapsulated Fish Oil Additives on Their Physicochemical, Microbial and Sensory Properties.

The aim of the study was to evaluate the influence of refined fish oil additives in liquid and microencapsulated forms, packing method (VP-vacuum packing, MAP-modified atmosphere packing) and storage time (1, 7, 14, 21 days) on selected physicochemical, microbiological and sensory characteristics of minced poultry sausage. Principle component analysis (PCA) showed that the fish oil additive, packing method and storage time significantly influenced some of the physicochemical characteristics of the sausages. The pH value was negatively correlated with the type of sample and packing method. The water activity decreased along with the storage time. The sausages with microcapsules had distinguishable hardness, gumminess and chewiness than the other samples. This tendency increased in the subsequent storage periods. The packing method and storage time of the samples had a statistically significant influence on the growth of the total colony count and count of lactic acid bacteria (p < 0.05). The most aerobic bacteria were found in the control sample, and the least in the sample with microcapsules, regardless of the packing method. The use of MAP and the addition of microcapsules resulted in the lowest microbiological contamination of the sausages. The sensory analysis made by a trained panel did not show any significant differences between the samples. After 21-day storage of the sausages there was a slight decrease in some of the sensory parameters, e.g., color, smell, taste. The liquid oil and microencapsulated oil additives in the meat filling did not negatively affect the taste or any physicochemical characteristics of the meat products. From the microbiological perspective, there were better effects from the MAP method.

Influence of fish oil and microencapsulated fish oil additives on water binding and the rheological properties of poultry sausage batters.

BACKGROUND: The composition of meat batters can be modified by the addition of fish oil or microencapsulation of oil. Such modifications affect the water binding and the rheological properties of the resulting systems. There is little information available on the behaviour of water molecules in model meat batter systems with microcapsules. The main goal of the study was to assess the degree of water binding by the meat batter system and to carry out a rheological analysis during heating and cooling. RESULTS: The sample with the microcapsules was characterized by a slightly elevated level of total protein. The encapsulated oil additive reduced the pH and water activity value in the meat batter, compared with the control sample. There was one relaxation time T1 and two time components T2 in the control batter and the batter containing encapsulated oil. The sample with the oil additive was characterized by two components of relaxation time T1 and three components of relaxation time T2 . There was an inverse correlation between the dynamic viscosity of the batters and the spin-spin relaxation times T21 and T22 . The temperature courses of the modulus of elasticity in all the systems exhibited three areas of change (20-43 °C, 43-60 °C, and >60 °C). The highest dynamics of change in the modulus of elasticity was observed for the initial and final temperature range (60-85 °C). CONCLUSIONS: The samples with the oil and microcapsule additives exhibited higher elastic energy accumulation capacity and dynamic viscosity than the control batter within the whole heating range. The fish oil microcapsules improved the mechanical properties of poultry sausage batters and their water-binding properties. This may increase the juiciness and microbiological stability of the finished products. © 2020 Society of Chemical Industry.

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.

Classification of Dried Strawberry by the Analysis of the Acoustic Sound with Artificial Neural Networks.

In this paper, the authors used an acoustic wave acting as a disturbance (acoustic vibration), which travelled in all directions on the whole surface of a dried strawberry fruit in its specified area. The area of space in which the acoustic wave occurs is defined as the acoustic field. When the vibrating surface-for example, the surface of the belt-becomes the source, then one can observe the travelling of surface waves. For any shape of the surface of the dried strawberry fruit, the signal of travelling waves takes the form that is imposed by this irregular surface. The aim of this work was to research the effectiveness of recognizing the two trials in the process of convection drying on the basis of the acoustic signal backed up by neural networks. The input variables determined descriptors such as frequency (Hz) and the level of luminosity (dB). During the research, the degree of crispiness relative to the degree of maturity was compared. The results showed that the optimal neural model in respect of the lowest value of the root mean square turned out to be the Multi-Layer Perceptron network with the technique of dropping single fruits into water (data included in the learning data set Z2). The results confirm that the choice of method can have an influence on the effectives of recognizing dried strawberry fruits, and also this can be a basis for creating an effective and fast analysis tool which is capable of analyzing the degree of ripeness of fruits including their crispness in the industrial process of drying fruits.

Effect of microencapsulated fish oil powder on selected quality characteristics of chicken sausages.

BACKGROUND: Encapsulation of fish oil for use as oil powder for the human food industry offers new product design possibilities. The fat content of fish is unique in the amount of of long chain n-3 fatty acid that it contains. It can be expected that developing innovative food products with significantly improved nutritional value can simultaneously affect their rheological and sensory qualities in different ways. The present study aimed to compared the influence of the addition of fish oil and microencapsulated fish oil on the mechanical, structural, and sensory properties of poultry sausages during 21-day storage. RESULTS: In comparison with other systems, sausages enriched with microencapsulated fish oil were characterized by a greater capacity to accumulate potential strain energy (G') and by statistically significantly greater hardness measured in all the storage periods that were tested. The sausages enriched with microencapsulated fish oil were characterized by higher water activity than the other sausage variants. The analysis of cryo-scanning electron microscopy (cryo-SEM) images indicated the presence of a large evenly dispersed oil phase and microcapsules in the structure of the sausages. The sample with the addition of microcapsules was characterized by higher values on the smell and consistency parameters. CONCLUSION: The better results in the sensory evaluation of the structural parameters of the sample with microcapsules were consistent with the results of instrumental assessments. The use of microencapsulated fish oil powder as an ingredient of chicken sausages therefore seems to be a promising concept. © 2019 Society of Chemical Industry.

An evaluation of the mechanical and sensory characteristics of selected foodstuffs for senior citizens.

BACKGROUND: The population of Poland is one of the fastest ageing communities in Europe. Due to people’s ageing it is necessary to adapt the daily diet to these consumers’ requirements. The potential producers of food for senior citizens must allow for elderly people’s possibilities to consume meals (the structural aspect) and their nutritional needs. The aim of the study was to perform an instrumental analysis of the mechanical properties and sensory evaluation of selected foodstuffs for senior citizens. METHODS: The foodstuffs were purchased in Japan. There were three meat and vegetable stew products and two creamy soup products. The texture of the samples was analysed at temperatures of about 22°C and 55°C by means of a shear test or with a penetrometer. Dynamic mechanical thermal analysis was applied to characterise the rheological traits of the samples heated to temperatures of 22–55°C. The finished products were evaluated by a ten-member panel trained in accordance with the requirements of PN-EN ISO 8586: 2014-03. RESULTS: The values of the texture parameters of all the samples were low and they were even more significantly reduced when the products were heated. The dynamic viscosity of the systems showed their relatively high density. Among the meat and vegetable dishes, dish no. 2, i.e. beef with vegetables, had the highest score in consumer preferences, i.e. 91.1%. Among the cream soups, sample no. 5, i.e. chicken & vegetable, had the highest score, i.e. 83.8%. The evaluation panel noted that the products were not sufficiently flavoured. CONCLUSIONS: The results of the instrumental and sensory tests showed that the products for senior citizens had desirable structural characteristics, which are important for their consumption. As the issue of food for senior citizens is important for consumers all over Europe, it is necessary to consider the taste preferences of consumers inhabiting a particular geographical region (traditional flavours) before such foodstuffs are offered on the market.

Kinetic models of quality parameters of spreadable processed Gouda cheese during storage.

The aim of the study was to prepare mathematical models based on the Arrhenius equation as predictive tools for the assessment of changes in quality parameters during the storage of spreadable Gouda cheese at temperatures of 8, 20 and 30 °C. The activation energy value and the chemical reaction rate constant enabled the construction of kinetic models, which helped to estimate the direction and rate of changes. Moreover, the activation energy (Ea) of the quality parameters was used to determine the sequence of their vulnerability during storage. The value of activation energy corresponding to temperature changes resulted in the following order of susceptibility of the quality parameters: ΔC > ΔE ≈ water activity > texture parameters > pH > colour > sensory parameters > rheological parameters. The research showed limited applicability of the mathematical models for estimation of quality parameters referring to spreadable processed Gouda cheese.

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. 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 coefficient 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.