Abstract:
The 8-month-old young coconut fruit after coconut spadix open is suitable for eating fresh because kernel has 2-2.5 layers and liquid endosperm are strongly fragrance. Generally, coconut harvesting prefers to gather in bunch which may affect the quality properties since fruit age and size vary considerably in coconut cluster. Thus, this research emphasized on the difference in quality properties of young coconut fruit in each bunch and changing in their quality properties after harvest. Fragrant coconut (Ma Prao Nam Hom) had the average weight of fruit per bunch 12.06 kg and the average weight of each fruit 1.79 kg. Fruit surface had pale green (YGG144 GBA) color. Fruit size in each bunch could be classified into 3 groups according to fruit weight: small (1200-1500 g), medium (1501-1800 g) and large (>1800 g). The highest kernel thickness was found at stylar end zone and progressively decreased to stem end zone whereas eating quality resulting from SS/TA ratio and pH was not different among fruit sizes.
For quality properties changing after harvest, coconut fruit stored at room temperature 26±3°C had higher weight loss percentage 2 times than one kept in low temperature 10±3°C Percentage of weight loss was related to the increasing of storage time. Kernel thickness of coconut fruit stored at room temperature increased in accordance with the longer storage time, especially at the bottom, when compared to one kept in 10±3°C as well as kernel firmness which increased along with kernel thickness. Nut cavity pressure rose from day 2 and declined on day 10 of storage which related to the amount of dissolved carbon dioxide while the number of dissolved nitrogen and oxygen in liquid endosperm had a bit of alterations during storage. Soluble solids of coconut water kept in both temperatures were similar but titratable acidity in this endosperm stored at 10±3°C had higher quantity with regard to the increasing of pH value. Stored liquid endosperm in both temperatures had higher level of glucose than fructose and
sucrose, respectively whereas alkaline and neutral invertase activities in coconut water from fruit kept in 10±3°C were remarkable than acid invertase activity. Peroxidase activity in liquid endosperm from fruit stored in 26±3°C was sharply elevated from the beginning of storage in addition to lypoxygenase in both liquid and solid endosperm from fruit stored in 26±3°C had higher activity 2 times than one kept in 10±3°C