The effects of different drying methods on the quality of persimmons
學生姓名:
王彥婷
指導教授:
張祐維
學期:
113上
摘 要:
Persimmons (Diospyros kaki) are a nutrient-rich fruit, containing high concentrations of carotenoids and ascorbic acid, which provide various health benefits. However, persimmons are prone to spoilage and difficult to transport and store. Therefore, finding appropriate drying processing techniques is crucial. According to the first two papers, three main drying methods were used to dry persimmon slices: hot air drying (HAD), combined hot-air-microwave drying (CHAMD), and freeze drying (FD). Compared to the other two methods, the FD method can retain a higher content of nutrients, such as β-carotene, ascorbic acid, and total phenol content, but it requires longer time and higher costs. In contrast, the high temperatures used in HAD can reduce the drying time but also lead to significant nutrient loss (like ascorbic acid, titratable acidity, and arbutin) and may cause the cell structure to shrink or even change shape, thereby affecting its rehydration ability. With advancements in technology, researchers have found that combining two or more drying methods can yield better results. The CHAMD can produce colors, structures, and textures similar to FD while not requiring large amounts of energy and cost. The optimal CHAMD conditions identified in this report are a slice thickness of 1 mm, a temperature of 70°C, an initial hot air drying airspeed of 1.0 m/s, and a subsequent microwave drying power density of 10.7 W/g. In summary, using a combined drying method or adjusting the temperature during the hot air drying process can help the samples achieve nutrient content similar to that of freeze drying. Furthermore, carotenoids are not significantly affected by HAD. However, it can lead to the degradation of cell walls and membranes, exposing them to conditions that reduce their antioxidant activity.
王彥婷.pdf