Anna Onopiuk

Influence of post-mortem muscle glycogen content on the quality of beef during aging

Abstract Introduction: Glycolic changes which occur post-mortem have an impact on the physical and sensory features of beef, which in turn determine the successive processes and influence such beef quality traits as colour, tenderness, and cooling loss. The aim of this study was evaluation of the post-mortem changes in bovine meat during aging, quantitative analysis of glycogen and lactic acid, as well as examination of their impact on technological and sensory quality of selected muscles from Holstein-Friesian × Limousin breed carcasses. Material and Methods: The study included three muscles of different metabolic qualities and sarcomere length: m. semitendinosus, m. longissimus dorsi, and m. psoas major, collected from nine bull carcasses aged 24 ±2 months. Results: Significant correlations were found between the volume of cooling loss on individual days of aging and the pH value of muscle tissue, lactic acid and glycogen content, as well as beef lightness. However, no significant dependency between the volume of glycogen and the intensity of red and yellow colours was detected. Conclusion: The colorimetric analysis of glycogen and lactic acid can be an effective tool in predicting the quality of beef.

The impact of ozone on health-promoting, microbiological, and colour properties of Rubus ideaus raspberries

ABSTRACT The purpose of the study was to define the impact of ozonisation duration and concentration on selected chemical, physical, and microbiological properties of Rubus ideaus red-fruited raspberries of the Polka variety. Raspberry fruit was exposed to a stream of ozone in concentration of 0.3 and 0.9 mg/L over a period of 60 and 120 min. The scope of the study covered the measurements of titratable acidity, soluble solids concentration, and such health-promoting indicators as content of phenol compounds, flavonoids, anthocyanins and vitamins C, total antioxidant activity (TAA) on 0, 4th, and 8th day of storage. The ozone treated fruit had higher level of phenol compounds and demonstrated higher TAA compared to untreated raspberries. The use of ozone made it possible to curb the development of yeast and moulds on the surface of raspberries, in which the dosage of 0.9 mg/L and treatment time of 60 min proved most efficient.

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.