Conservação de espinafre (Tetragonia expansa) pelo emprego de radiação gama: aspectos físico-químicos, microbiológicos e sensoriais

Abstract

monocytogenes and STEC were evaluated in spinach samples exposed to doses of 1.0, 1.05 and 0.85 kGy, respectively, and in non-irradiated samples, stored for 12 days at (4±1) °C and (10±1) °C. The results showed that the populations of Salmonella and STEC were reduced at about 6 log, on day zero, and remained below the detection limit (<10 CFU/g) even after 12 days of storage at both temperatures tested. The 1.05 kGy dose reduced the population of L.monocytogenes in approximately 5 log, but in the samples stored at (10±1) °C, the growth of the microorganism (2,62 log) was observed at the end of the storage time.Spinach samples exposed to 1 and 1.5 kGy, as well as the control sample, all kept under refrigeration (4±1) °C were used for the evaluation of the product shelf life, sensory analysis, color analysis, determination of ascorbic acid, flavonoids, phenolic compounds and the antioxidant capacity. The samples exposed to 1 kGy displayed a shelf life of 15 days, two days longer than that observed for the control sample, while 9 those exposed to 1.5 kGy showed a shelf life of 12 days. All samples exposed to radiation were accepted by the sensorial panel. The irradiation had no significant effect either on the concentration of phenolic compounds or on the antioxidant activity. Nevertheless, there was a reduction in the concentration of flavonoids and change on the color. The color, phenolic compounds concentration and antioxidant activity were influenced by the seasons of the year. Although the change in color was observed by instrumental analysis, this was not perceived by the panelists during sensory analysis. The irradiation process is a great alternative for microbiological safety purpose together with Good Manufacturing Practices.

Physical, chemical, sensory and mineral characterization of salty muffins enriched with Tetragonia tetragonoides

“…The predominant presence of dark green is associated with chlorophyll, a bioactive compound with anti-cancer properties, in addition to inhibiting free radicals (Rocha & Reed, 2014). The other coordinates did not show significant differences (p > 0.05), although Rezende (2013) reported brightness values similar to that of this work for spinach leaves (L* = 35.10) and the b* coordinate (18.10).…”