Effects of Ultrasound Pretreatment on the Quality of Pineapple Ring Snacks

Increasing interest in prolonging shelf life and enhancing availability has led to the exploration of pineapple fruits for their nutritional benefits. Pineapple is one of the most consumed tropical fruits globally due to its exceptional sensorial qualities and numerous health-promoting components. However, its high moisture content (81–86%) poses challenges to long-term preservation, leading to significant postharvest losses. Drying, when combined with pretreatment techniques such as ultrasound, is an effective method to enhance preservation while maintaining nutritional quality. This study investigated the effect of ultrasound pretreatment on the quality characteristics of pineapple ring snacks processed using cabinet and solar drying methods. Fresh Queen pineapple was washed, decrowned, peeled, cored, sliced, and subjected to ultrasound pretreatment before drying. Four sample variations were produced: two with ultrasound pretreatment and two controls, representing both drying methods. The results revealed that ultrasound pretreatment significantly enhanced drying efficiency and nutrient retention. The sample AGY (cabinet dried with ultrasound) had the lowest moisture content (5.12%) and retained the highest levels of fat (0.59%), ash (1.56%), fiber (2.11%), and carbohydrate (86.54%), compared to the untreated control CHM. AGY also recorded the highest Vitamin C content (41.28 mg/kg) and better retention of vitamins A and B-complex compared to other samples. Mineral analysis showed AGY and AHE (solar dried with ultrasound) had significantly higher calcium, magnesium, and potassium levels than their untreated counterparts. The AGY sample also demonstrated lower total titratable acidity and higher pH (0.66), indicating reduced acidity. Sensory evaluation showed that ultrasound-treated samples, particularly AGY, were most preferred in terms of color, taste, texture, and overall acceptability. In conclusion, ultrasound pretreatment proved effective in enhancing the quality of dried pineapple ring snacks by improving nutritional value, microbial safety, and sensory appeal.