Freezing, thawing and cooking effects on quality profile assessment of green beans (cv. Win)

The objective of this study was to analyze the effect of freezing and different culinary treatments (stir-fried and steamed) on the nutritional composition, bioactive compounds, and sensorial characteristics of zucchini. The zucchini was stir-fried for 8 min at 250ºC and steamed for 13 min at 100ºC. The freezing of raw zucchini did not significantly affect its nutritional compounds. The stir-frying process provoked important moisture loss; this being higher when zucchini was previously frozen. The content of ash, proteins and fats significantly increased in stir-fried zucchini. There was an important decrease in antioxidant activity and phenolic compounds when the zucchini was frozen. The antioxidant activity was much greater in the stir-fried produce in comparison to steamed and raw. Freezing the raw zucchini provoked a significant loss in its adhesiveness qualities and hardness. A lower hardness and adhesiveness were also observed in frozen zucchini after steamed and stir-fried, these changes were not being observed in freezing. The sensorial characteristics of previously frozen zucchini were valued less by the consumer as well as those that were steamed and stir-fried. The culinary treatment affected the sensorial values less and only better were observed in fresh steamed zucchini than the stir-fried.

Section: Introductionmentioning

confidence: 99%

Nutritional and sensorial characteristics of zucchini (Cucurbita pepo L.) as affected by freezing and the culinary treatment

Tejada

Buendía−Moreno

Villegas

et al. 2020

“…[14] MW processing conditions should be optimized with the aim of reducing degradation of nutrients to a minimum level. [23,24] For this reason, there is a need for the studies of degradation kinetics. In the literature, there is only one study on the effect of MW processing on the kinetic modeling of physiochemical properties of vegetables (i.e.…”

Section: Introductionmentioning

confidence: 99%

Degradation kinetics of bioactive compounds and antioxidant capacity of Brussels sprouts during microwave processing

Nakilcioğlu-Taş

Ötleş

2017

In this study, the effects of microwave (MW) processing of Brussels sprouts on various bioactive compounds, moisture content, and antioxidant capacity were studied. Brussels sprouts was processed at three different MW output powers (460, 600, and 700 W), and then kinetic study for the degradation of the total chlorophyll, vitamin C, total polyphenols, total flavonoids, antioxidant capacity, and two phenolic acids (sinapic and ferulic acid) was conducted. According to the results, MW processing caused significant reductions in analyzed bioactive compounds, moisture content, and antioxidant capacity. It was found that HPLC analysis results confirmed the result of the spectroscopic analysis. Zero-order and first-order kinetic models were fitted to experimental data. The first-order kinetic model was selected as the best according to R 2 , RMSE, and χ 2. The degradation rate constant (k) for all analyzed properties increased as the MW output power increased from 460 to 700 W, and it could be concluded that the MW output power in which bioactive compounds, moisture content, and antioxidant capacity of Brussels sprouts were best preserved was 460 W.

“…However, slow-freezing produces substantial amounts of large ice crystals in the extracellular areas and causes significant damage to the tissue in which they are formed. [45][46][47] Ferreira et al, [48] confirmed that rapid freezing was beneficial for the texture of green beans. Furthermore, employing the quick-freezing method facilitates the formation of a large number of nuclei with small and evenly distributed ice crystals, therefore, resulting in less damage to the structure of the food and reducing the drip loss.…”

Section: Resultsmentioning

confidence: 94%

Microstructure and quality of cabbage slices ( Brassica oleracea L. var. capitata L.) as affected by cryogenic quick-freezing treatment

Wang

Xing

et al. 2019

In this article, the influence of various cryogenic quick-freezing preservation methods on the quality and microstructure of cabbage (Brassica oleracea L. var. capitata L.) slices were investigated during a 28 d storage period. The results indicated that when compared to other methods, the microstructure of the cabbage slices that were frozen cabbage using dry ice displayed the least amount of modifications when stored. The content of chlorophyll, vitamin C (V C), and titratable acidity (TA) in these samples presented minimal changes at the end of storage, which were 1.5147 mg/g, 26.2 mg/100 g, and 0.2623%, respectively. Moreover, the samples exposed to dry ice freezing exhibited the highest content of total sugar that reduced following 28 d of storage. In addition, this combined treatment prevented textural changes in the cabbage slices. For these samples, the values representing the hardness, chewiness, springiness, and cohesiveness were 47.01 N, 14.54 N mm, 1.5147 mm and 3.363, respectively. Furthermore, dry ice freezing treatment could mostly retard the microbiological degradation of the cabbage slices. Finally, the sensory quality of samples treated with dry ice freezing scored 6.4 at the conclusion of the storage period. The samples that were frozen at −60°C displayed enhanced preservation properties, while the sensory quality scored only 5.2. These results indicated that dry ice freezing treatment and storage at −18°C could maintain the microstructure and nutritional quality of cabbage slices.