INFLUENCE OF HARVESTING DATES ON FRUIT QUALITY AND STORAGE PERFORMANCE OF SWEET ORANGE (BLOOD RED) FRUIT - A. Rab; J. Rahman; M. Sajid; N. Ahmad; M. Ahmad; K. Nawab; K. Ali (Journal of Animal and Plant Sciences, 2016)
The influence of harvesting dates on storage performance of sweet orange fruits was investigated by harvesting the sweet orange fruit from November 15th to February 15th and storing for 30 days at room temperature. The means total soluble solids (TSS) content (8.383%), TSS/Acid ratio (6.51) and reducing sugars (2.76%) in fruit harvested on November 15th increased to the maximum of 14.15%, 43.13 and 11.19% accordingly when the fruits were harvested on February 15th. By contrast, the acidity (1.39%) and non-reducing sugars (4.88%) in fruits harvested on Nov.15th, declined to the minimum of 0.51, and 4.11%, respectively in fruits harvested on February 15th. The juice content (37.90%) and ascorbic acid (41.03 mg/ 100 ml) in fruits harvested on November 15th increased to the highest of 53.05% and 56.40 mg/ 100 ml for January 15th harvest but thereafter declined to 35.99% and 40.90 mg/ 100 ml, respectively in fruits harvested on February 15th. The storage of sweet orange fruits increased the mean TSS from 11.23 to 12.24% and reducing sugars from 6.62 to 8.12% but decreased the acidity from 1.17 to 0.75% and ascorbic acid from 65.02 to 55.40 mg/ 100 ml. The interaction of harvesting date and storage revealed a significant influence on the TSS/ acid ratio, reducing sugars, juice percentage and ascorbic acid content of sweet orange fruits. The TSS/Acid ratio was not significantly affected by storage in fruits harvested from November 15th to January 15th but was significantly higher in fruits harvested from January 30th to February 15th. The reducing sugars of sweet orange fruit increased from 3.32% in fruits harvested on November 15th to the maximum of 12.32% with delaying the harvesting to February 15th. However, at each harvesting date, the difference in reducing sugars content of fresh and stored sweet orange was not significant. The ascorbic acid content of fresh fruits was the least (54.59 mg/100ml) in fruit harvested on November 15th and increased to the maximum (76.21 mg/100ml) in fruit harvested on January 15th, but declined significantly in fruit harvested on January 30th or February 15th. Storage decreased the ascorbic acid content non-significantly in fruits harvested from November 15th to December 15th. However, delaying harvesting to December 30th and February 15th resulted in significantly lower ascorbic acid content of stored fruits as compared to fresh fruits. The juice content of fresh fruits harvested on November 15th (41.03%) increased to the maximum (56.40%) in fruit harvested on January 15th but thereafter decreased significantly in fruit harvested on January 30th or February 15th. The juice content decreased the significantly with storage so that it was lower than the fresh fruits irrespective of the harvesting dates. The weight loss after 30 days storage was the highest (7.27%) of fruits harvested on November 15th, declined to the least (4.17%) in November 15th harvest but increased to 5.91% in fruits harvested on February 15th. By contrast, oleocellosis incidence was the least (3.33%) of fruit harvested on November 15th and increased significantly with incremental delay in harvesting and was the highest (26.67%) in fruit harvested on February 15th.
Keywords: journal article; Ascorbic acid; Citrus; Harvesting Date; pH; Sugars; storage; TSS; TSS/ Acid ratio