Production and quality characteristics of readt-to-cook pumpkin prepared with quicklime application

Pumpkin, originating from Latin America, is widely used in a variety of products ranging from soups to desserts. In Turkey, however, it is predominantly consumed as candied pumpkin prepared with lime treatment. Due to its content of carotenoids and vitamins A and E, pumpkin is considered highly valuable in terms of health benefits. Nevertheless, the increasing prevalence of fast consumption habits has rendered the traditional preparation of candied pumpkin more laborious. The shelf life of fresh pumpkin after cutting is limited to only 1–2 days, and its large volume restricts utilization, as it cannot be consumed rapidly. In this study, an unhydrated lime pre-treatment was applied to pumpkin to shorten the processing time required for candied pumpkin production. Slices of pumpkin (3 cm thickness) were immersed in a saturated unhydrated lime solution (0.125%) with stirring for 6 h, vacuum-packed, and stored at +4 °C for 3 months. During storage, analyses of color, texture, pH, Brix, total viable counts, and yeast–mold counts were performed at monthly intervals. Calcium oxide (CaO) treatment was found to increase the brightness of pumpkin, while simultaneously decreasing the +b value, which is associated with yellowness. When the time factor was disregarded, the unhydrated lime treatment had no significant effect on pumpkin firmness (p > 0.05). However, during storage, lime-treated samples retained their firmness better than the control during the first two months. Calcium oxide treatment was found to increase the pH value of pumpkin. Immersion in calcium oxide solution reduced the water-soluble solid content of the pumpkin samples. The analyses revealed that there was no statistically significant difference in the total viable bacterial counts between the control group and pumpkins treated with quicklime (p > 0.05). While the total viable bacterial count in the quicklime-treated group remained stable throughout the storage period, the control group exhibited a significant increase in the third month. Yeast and mold analyses indicated that no mold growth was detected in the pumpkins. Furthermore, it was determined that the antioxidant capacity of the quicklime-treated pumpkins decreased progressively during storage, whereas the control group maintained its antioxidant stability during the first two months.