Monalisa K, Bhuiyan J A, Islam M Z, Sayem Asm
Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet, Bangladesh.
Department of Advanced Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan.
Food Sci Technol Int. 2020 Jun;26(4):333-343. doi: 10.1177/1082013219894402. Epub 2019 Dec 17.
The objective of the present study was to evaluate the effect of boiling duration on physicochemical, bioactive compounds, antioxidant activity, color, and texture properties of pumpkin (). The pumpkin was subjected to boiling for 1, 5, 10, and 20 min at 100 ℃. The physicochemical analyses showed that pH, moisture, and water solubility index were increased, whereas ash content was decreased with increasing the boiling time. Prolong boiling exhibited a detrimental effect on bioactive compounds of pumpkin, and it was found that 20 min of boiling caused about 25.91% ± 2.21% loss of total phenolic content, 14.79% ± 1.03% loss of total carotenoids content, and 18.46% ± 1.34% loss of antioxidant activity. A kinetic study was conducted to quantify the losses occurring in bioactive compounds, antioxidant activity, changes in color, and firmness of pumpkin. The study revealed that the logistic model can predict the variation in bioactive compounds and antioxidant activity with higher R. However, first-order kinetic models were found suitable to predict the changes occurring in bioactive compounds, antioxidant activity, color properties (L*, a*, b*, Chroma), and firmness. The total color changes (ΔE) showed a good fit with zero-order kinetic models (R= 0.98). The t and D-value were calculated for all measured parameters of pumpkin. These findings would be useful in designing thermal processes and related calculations of pumpkin.
本研究的目的是评估煮沸时间对南瓜理化性质、生物活性成分、抗氧化活性、颜色和质地特性的影响。将南瓜在100℃下分别煮沸1、5、10和20分钟。理化分析表明,随着煮沸时间的增加,pH值、水分和水溶性指数升高,而灰分含量降低。长时间煮沸对南瓜的生物活性成分有不利影响,发现煮沸20分钟导致总酚含量损失约25.91%±2.21%,总类胡萝卜素含量损失14.79%±1.03%,抗氧化活性损失18.46%±1.34%。进行了动力学研究,以量化生物活性成分、抗氧化活性、颜色变化和南瓜硬度方面的损失。研究表明,逻辑模型可以较高的R值预测生物活性成分和抗氧化活性的变化。然而,发现一级动力学模型适合预测生物活性成分、抗氧化活性、颜色特性(L*、a*、b*、色度)和硬度的变化。总颜色变化(ΔE)与零级动力学模型拟合良好(R = 0.98)。计算了南瓜所有测量参数的t值和D值。这些发现将有助于设计南瓜的热加工过程及相关计算。