Water blanching conditions on the quality of green asparagus butt segment (Asparagus officinalis L.)

The butt segment of asparagus contains numerous nutrients, including various antioxidants. In particular, fibers and several mineral contents are quite high. However, asparagus butt segment quality is reduced in processing. Therefore, research on the asparagus butt segment processing for development of food industry and for the benefit of economic is necessary. Water blanching is a pretreatment method applied in most fruit and vegetable industry today. Water blanching process can inhibit enzyme activity and reduce loss of food quality. However, water blanching can lead to loss of nutrient contents as well as changes in color and texture (sensory values). In this study, the temperature was investigated at 70 degrees C, 75 degrees C, 80 degrees C, 85 degrees C and 90 degrees C, and the blanching time was observed at 2, 4, 6, and 8 minutes. We evaluated the effect of blanching conditions through the percent retention of vitamin C, phenolic compounds, antioxidant capacity (DPPH assay), and changes of sensory values. The results show that blanching temperatures from 75 degrees C to 85 degrees C insignificantly affect quality of asparagus butt segment. However, nutrient contents and sensory values decrease rapidly with the increase of blanching time. When asparagus was blanched at 85 degrees C for 4 minutes, the percent retention of vitamin C, phenolic and antioxidant capacity was 74.84% 80.34% and 71.24%, respectively. These results suggested the good blanching conditions for asparagus butt segment processing. (C) 2019 Elsevier Ltd. All rights reserved.