CHANGES IN APPARENT VISCOSITY AND VITAMIN C RETENTION DURING THERMAL TREATMENT OF BUTTERNUT SQUASH (CUCURBITA MOSCHATA DUCH) PULP: EFFECT OF RIPENING STAGE

Abstract

The effects that ripening stage have on the apparent viscosity and ascorbic acid retention in squash pulp exposed at cooking process were analyzed. Total soluble solids contents were taken as indicative of ripening degree. In the raw material, water contents ranged from 79 to 96%, but no significant differences were observed among samples grouped as unripe, ripe and overripe. The ascorbic acid contents of pulp increase with increases in soluble solids contents. Pulp from unripe and ripe squash had similar apparent viscosity values; however, lower viscosity values were obtained in pulp from overripe squash. During heat treatment, significant changes in the apparent viscosity values of pulp from unripe and ripe squash were observed. Heat penetration properties of squash pulp indicate correlation between the inverse slope of the straight portion in the heat penetration curves on a semilog plot (fh) and thermal diffusivity values (α) with dry matter content, but no correlation was found with squash maturity degree. High ascorbic acid retention (82%) in pulp held for 30 min at 95C was found independently of squash maturation degree. PRACTICAL APPLICATIONS Knowing the rheological behaviour and the ascorbic acid retention of butternut squash pulp during cooking process could be used as a valuable information previously to make decisions for use this crop as a food supply.

EVALUATION AND UTILIZATION OF SOME EGYPTIAN PUMPKIN (Cucurbita moschata) CULTIVARS

“…While Edwa and Kafr-El-Batikh cultivars recorded low values (2.30 and 3.90 mg/100g, respectively). The high values of vitamin C in Qina and Kafr-Saad cultivars were similar that reported by Walker (1978) and Roura et al (2007) who found that vitamin C in pumpkin was 30 and 22.87 mg/100g, respectively. While the low values of Edwa and Kafr-El-Batikh cultivars were agreement with the results of Sudhakar et al (2003) and Marina et al (2009).…”

Chemical and Physicochemical Characterization of Winter Squash (Cucurbita moschata D.)

“…Tamer et al (2010) reported lower values of L* (49.6) and higher values in a* (21.9) and b* (31.0). Soluble solids determined in the present experimental work were lower than the reported by Roura et al (2007) and Noseworthy and Loy (2008) (8-11 and 7.0-8.7 °Brix, respectively) for C. moschata. The pH values were higher than the reported by Tamer et al (2010) (5.80) in C. moschata.…”

Dynamics of Selected Bioactive Substances Changes in Cucurbita Moschata Duch. Ex Poir. After Storage and Different Methods of Technological Processing

“…Because the preparation and stabilization of home-cooked products, such as soups and sauces from squash pulp, would involve thermal treatments, the ascorbic acid retention in squash pulp held for 30 min at 95 o C was investigated. The percentage of ascorbic acid retention was 82.43 + 2% (Roura et al, 2007). On the basis of our results there can be confi rmed conservation of vitamin C, providing the thermal treatment -baking, only on 61% in average in case of all observed varieties (Tab.…”