The analyzed data as stated in the Table 1, it was observed that PLW (%) of cucumber fruits increased progressively with the advancement of storage periods and it was found out to be statistically significant (P<0.01) among all treatments (including parents, hybrids and check). Among parents, BRGCU-4 exhibited the lowest PLW% ranging from 2.53 to 8.64 from 1
st to 7
th day of storage (Table 1), which was significantly superior to rest of the parental lines taken under investigation. In hybrids, cross of BRGCU-4 × BRPCU-6 showed the minimum PLW as 10.90%, followed by BRGCU-4 × BRPCU-8 as 11.33%. The rapidly loss of weight of fresh fruits may be due to lower level of relative humidity (RH) at ambient condition. These results were in agreement with
Manjunatha and Anurag (2014),
Omoba and Onyekwere (2016),
Jia et al., (2018) and
Raghav and Saini (2018) in cucumber.
The total soluble solids (°Brix) of fruits were measured at the first, 4
th and 7
th day of storage period (Table 2) and it was found out to be statistically significant (P<0.01) for all treatments (including parents, hybrids and check). At ambient conditions, the TSS of cucumber fruits showed a gradual decrease. Being a basic constituent of TSS, sugar was used in respiration for metabolic activities of fruits and vegetables (
Ozden and Bayindirli, 2002;
Raghav and Saini, 2018), therefore reduction in TSS content was recorded. The parental lines BRPCU-7 and BRPCU-8 and hybrids of BRPCU-3 × BRPCU-7 and BRPCU-2 × BRPCU-8 were found significantly superior as they showed highest TSS during storage period. This result was in agreement with the findings of
Jia et al., (2018) in cucumber.
The results of firmness of all cucumber fruits stored at ambient conditions for a period of week decreased sharply (Table 2) and all the treatments were found out to be significantly different (P<0.01). The parent BRGCU-4 showed significantly highest value of firmness during storage periods, while crosses BRGCU-4 × BRPCU-6, BRGCU-4 × BRPCU-5, BRGCU-4 × BRPCU-7 and BRGCU-4 × BRPCU-8 exhibited highest firmness but with non-significant differences from each other. The loss of firmness of fruits is a biochemical process that involved enzymatic hydrolysis of pectin and starch (
Raghav and Saini, 2018), or it was caused by composition of cell wall, deterioration of cell structure and intracellular membrane
Seymour et al., (1993), Dhall and Sharma (2012),
Moalemiyan and Ramaswamy (2012),
Manjunatha and Anurag (2014),
Omoba and Onyekwere (2016),
Jia et al., (2018) and
Raghav and Saini (2018).
The titratable acidity has shown a statistically significant (P<0.01%) difference among all the treatments (including parents, check and hybrids). The percentage value of titratable acidity was found out to be on slightly higher side and observed with decreasing
vis-a-vis stable trends during first four days of storage, but reducing trends were seen from day 4 to 7 (Table 2). The highest acidity was recorded in parents BRPCU-2 and BRPCU-8, while the hybrids of crosses BRPCU-3 × BRPCU-6 and BRPCU-1 × BRPCU-8 were reported with significantly higher acidity during storage. Organic acids like malic and citric acids are the basic substrate of respiration and decrement of acidity with storage is useful as it renders the fruits less sour and acidic (
Raghav and Saini, 2018). Similar results were reported by
Omoba and Onyekwere (2016) in cucumber.
The analyzed results of the level of chlorophyll contents and carotenoids are being described in the Table 3. These are the bio functionally important compounds that preserved both quality and attractiveness of fruits during storage. The highest amount of total chlorophyll was observed in the parents BRPCU-6 and BRPCU- 7, but at the end of the storage period, parent BRPCU-3 was reported with significantly higher amount of total chlorophyll. While, in case of hybrids, cross of BRPCU-3 × BRPCU-6 exhibited the minimum loss in chlorophyll content and exhibited significantly superior values than remaining hybrids during storage periods. The amount of chlorophyll a, b and total chlorophyll showed the decreasing pattern during storage periods. Similar trends were also reported by
Nilsson (2005),
Moalemiyan and Ramaswamy (2012) and Jia
et al., (2018) in cucumber. The amount of carotenoid in cucumber fruits of different parents and hybrids increased gradually during storage periods. In fresh cucumber fruits, the significantly higher amount of carotenoid was observed in parent BRPCU-7, while hybrid of BRPCU-7 × BRPCU-8 showed the highest carotenoid content during storage periods.