Jarosław Wyrwisz

ANALYSIS OF RELATIONSHIP BETWEEN BASIC COMPOSITION, pH, AND PHYSICAL PROPERTIES OF SELECTED BOVINE MUSCLES

Abstract The aim of this study was to analyse the correlation between basic meat composition (water, protein, fat, and connective tissue contents), pH value, and physical parameters (texture and colour, drip loss) of selected beef muscles. Five different muscles (LTH, SEM, SET, PSM, TRI) from 20 carcasses were examined. Measurements of the basic meat composition were conducted using a near infrared spectrometry method, colour parameters in L*a*b system, and texture parameters. Drip loss correlated strongly negatively with the pH value. Depending on the muscle type, the correlation ranged -0.601≤r≤-0.282, whereas drip loss correlated moderately positively with connective tissue content. The most significant positive correlation (r≈0.67) between hardness, tenderness, and fat content was noted in the SEM. Colour parameters strongly depended on pH values (-0.831≤rL*≤-0.338; - 0.828≤ra*≤-0.542; -0.912≤rb*≤-0.719) and to a lesser extent on the content of connective tissue.

Influence of 21 days of vacuum-aging on color, bloom development, and WBSF of beef semimembranosus

Changes of color, proportions of myoglobin forms, pH, Warner-Bratzler shear force (WBSF) of beef m. semimembranosus (SM) were examined during 21days of vacuum-aging. Significant changes in lightness, redness, yellowness, chroma, and hue angle (p≤0.05) of SM during aging were found. Proportions of myoglobin forms changed on the 7th day of aging. Aging decreased WBSF in general, but a significant decrease (p≤0.05) from 67.86N to 55.3N was observed after day 14 of aging. The color parameters (L*, a*, C, ΔE) and O2Mb in 21-day aged SM were stabilized faster during blooming. Beef SM that had faster stabilization of bright red color during blooming were more tender (correlation of O2Mb with WBSF r=-0.87; p≤0.001). This could be important information for the producers, since the best quality traits could be achieved after sufficient blooming and aging time.

Effect of packaging method and cold-storage time on chicken meat quality

This study was performed to determine the effects of vacuum packaging (VP) and modified-atmosphere packaging (MAP) (CO2/N2 = 3:7) on the physicochemical properties and sensory attributes in chicken breast meat during storage at 2ºC±0.5ºC for 5, 10 and 15 days. Results showed that storage time influenced the physicochemical properties, except sensory attributes, shear force and shear energy of chicken meat. The extended storage time was causing an increase in the pH value, drip loss and in values of color parameters (L, a* b*) in chicken meat. Moreover, the packaging method affected values of drip loss, cooking loss and shear force. Fresh meat (0 days of storage) was characterized by the highest overall quality assessed with the semi-consumer scaling method. Storage time and packaging method were found to exert significant effects on the physicochemical parameters determined instrumentally and on sensory attributes of meat evaluated with the semi-consumer scaling method.

Influence of the wheat flour extraction degree in the quality of bread made with high proportions of β-glucan

β-glucan is currently one of the most important bioactive substances. Hence, there is a growing interest in the production of various foods containing β-glucan. The study examines the influence of the degree of wheat flour extraction in the quality of breads with high β-glucan content. Rheological tests were conducted on dough. Volume, mass, color and texture of bread were measured after baking. We observed that increasing the degree of extraction caused an increase in the storage and loss modulus. All of the bread made from the different flours were smaller in volume after the addition of β-glucan, although the yield increased. The crumb color of β-glucan-added breads was darker than the control samples. Control samples were higher in textural parameters (firmness, gumminess and chewiness). β-glucan-added samples had decreased porosity. The results revealed that using very strong flour with a high protein content results in a high quality β-glucan bread with a higher nutritional value due to the high total dietary fiber and β-glucan content.

Combined use of cocoa dietary fibre and steviol glycosides in low-calorie muffins production

Summary Today, consumers are more conscious about nutrition and food products with health benefits. In this study, partial sucrose replacement (20%) with steviol glycosides derived from Stevia Rebaudiana and total replacement of cocoa powder with cocoa fibre preparation in muffins were conducted. There were three levels of dietary fibre addition – 3%, 6% and 12%. Physical analysis of texture, colour, cooking yield and porosity was conducted. Moreover, chemical analysis of total dietary fibre and total phenol content was made as well. Sensory evaluation in two parts was also carried out. The experiment revealed the increase in firmness, porosity, TDF and TCP and the decrease in springiness, cohesiveness and lightness. The best-ranked sample in sensory evaluation was muffin with 6% of TDF sweetened with mixture of sugar and stevia. Stevia addition enhanced cocoa and sweet taste in tested muffins.

Effect of β-glucan particle size on the properties of fortified wheat rolls

The effects of β-glucan particle size and the ratios of β-glucan to flour on the physicochemical properties of wheat rolls were examined. A total of 100, 195 and 280 µm particles were analyzed with flour replacement from 0% to 20%. Wheat rolls made with the various particles and flour replacement levels were measured for rheology, yield and volume, texture, color, porosity, total dietary fiber (TDF) content and β-glucan content. All products had a smaller volume compared to the control, whereas the lightness was not significantly affected. Texture analysis indicated that the most favorable textural values were observed for the formulation involving the 195 μm β-glucan particles. Rolls with the same flour replacement level using the smaller particles had a higher share of TDF due to the greater surface of water evaporation. The main finding from the research was that the best results in most measured parameters were observed using 195 µm dietary fiber preparation. Thus, particle size reduction might be used to improve product properties but only to a certain extent because the load of micronized fiber weakens the structure, resulting in decreased product quality.

Effect of oat β-glucan fiber powder and vacuum-drying on cooking quality and physical properties of pasta

Oat β-glucan fiber powder was added to pasta dough at levels of 40, 80, 120, 160, and 200 g/kg. Pasta was dried at very high temperature and in a vacuum dryer. The cooking quality was evaluated based on the swelling index, water uptake, and cooking loss measurement. Further tests were carried out to determine the color, hardness, adhesiveness, total dietary fiber (TDF), and β-glucan content in pasta. The results showed that vacuum-drying had a significant impact on the cooking quality and physical properties of pasta. Water uptake and swelling index were higher and the cooking loss was lower in vacuum-dried pasta than in pasta dried using very high temperature (VHT) technology. The swelling index, water uptake, and cooking loss were significantly higher in samples with oat β-glucan fiber powder compared to control. Pasta with oat powder was darker, softer, and less sticky than semolina pasta. Lightness of vacuum-dried samples was higher while redness was lower than in conventionally dried samples.

Impact of ozonisation on pro-health properties and antioxidant capacity of ‘Honeoye’ strawberry fruit

ABSTRACT The objective of the research was to determine the impact of concentration and ozonisation time on the selected chemical properties and total antioxidant capacity of ‘Honeoye’ strawberries cultivar. Efficiency of gaseous ozone usage as a method of extending the fruit shelf life was proved. Strawberries were exposed to ozone stream with concentration of 0.3–1.2 mg/L, within 60, 120, 150 and 180 min. The scope of research included measurements of the titratable acidity, content of soluble solid substances and the following pro-health characteristics: the total antioxidant capacity, phenolic compounds content and vitamin C content. On the second, fourth and sixth day of storage, an assessment was carried out on the fruit mass changes. Statistically significant differences (p < 0.05) in the titratable acidity changes and soluble solids concentration were reported. The application of ozone allowed reduction of strawberries weight losses during storage without a negative impact on their pro-health properties.

Dynamic Colour Changes Depending on the Temperature Inside the Final Beef Product in a Process of Frying and Grilling

Abstract Four different beef muscles (PM, SM, LTL, TB) were examined. These muscles were fried or grilled. Each muscle was observed at various internal temperatures: 60°C, 65°C, 70°C, and 75°C. At each temperature level, a measurement of colour was taken using a Minolta Chroma Meter CR-400 in a L*a*b* system. The values of the parameters L*, a*, and b* were measured on a cross-section sample (two areas) after cutting perpendicular to the fibres at the middle of its height. Area I was located at the central part of the steak with a diameter of 2 cm. Area II was located at a distance of 1 cm from the edge of the steak. From the results obtained, the difference in colour values between areas was noted. The results indicated that area I was lighter and redder in comparison to area II. The values of parameters L* and a* recorded in the first area were higher in comparison with the values from the second region, indicating that the sample in the area I was lighter and redder than in the area II at the outside of the sample. There was a large variation in the colour of the two areas. It was observed that for all sampled fried muscles, the highest difference in lightness (ΔL*) between the two test areas was obtained at a heat treatment temperature of Ti= 65°C inside the sample. With grilling the highest value for overall difference in colour between areas was from samples heated to a final temperature of Ti=60 °C.

Physical properties of muffins sweetened with steviol glycosides as the sucrose replacement

Overconsumption of sweets contributes to increasing obesity among children and adults. Functional food brings an opportunity to improve nutritional value of commonly eaten products, e.g., pastry products. New trends in the food industry tend to produce low-calorie products by replacing sugar or fat with additives having pro-health benefits. The aim of this study was to determine the effect of replacing sucrose with steviol glycosides (natural non-caloric sweetener) on the quality properties of bakery products. The analysis of muffin’s texture, color, cooking yield, browning index, and sensory analysis were performed. The study showed that a 25% addition of steviol sweetener (as a sucrose replacement) was the most appropriate modification of the basic formula. The resulting muffins gained sensory attractiveness and health-promoting qualities. Moreover, the study showed that a reduction of sucrose in excess of 50% had a negative impact on the quality of muffins and their sensory profiles.