Comparison Effect of Different Drying Methods on Physicochemical Properties and Antioxidant Activity of Pineapple Fruits

Abstract

Thanks to their high fiber, antioxidant activity, vitamin and mineral content, dried fruits are much healthier and more nutritious snacks than other processed snack foods. However, many research shows that certain compounds may degrade in the drying process, notably antioxidants, so drying method is very important to obtain desirable and healthy dried products. In this study, the comparison of quality characteristics of fluidized bed, microwave and vacuum dried pineapples was investigated. Pineapple slices were dried using fluidized bed dryer at 80 °C for 3 h. Vacuum drying treatments were performed using vacuum oven at 21.5 kPa and 60 °C for 12 h. Drying treatments in a microwave oven were performed at 360 W for 24 min. Color, rehydration capacity, shrinking ratio, antioxidant activity, total phenolic content measurements and sensory analysis were conducted in order to compare the physical, chemical and sensory properties of dried pineapples. Microwave dried samples had the highest L* value, total phenolic content and antioxidant activity compared to other samples (p < 0.05). On the other hand, vacuum dried samples took the highest flavor and overall impression values by the panelists (p < 0.05). When it was compared to other drying methods used in this study, fluidized bed drying caused the highest decrease in physicochemical, antioxidant activity and of pineapple samples. In the result of this study, it was revealed that being quick, cheap, and practical method, microwave drying has a promising potential for high-quality dried products.

Keywords

• Drying,Pineapple,Antioxidant activity,Sensory

References

1. Altuğ-Onoğur E, Elmacı Y (2011). Gıdalarda Duyusal Değerlendirme. İzmir, Turkey: Sidaş (in Turkish). Bolek, S., & Ozdemir, M. (2017). Optimization of roasting conditions of microwave roasted Pistacia terebinthus beans. LWT, 86, 327-336. Caparino, O. A., Tang, J., Nindo, C. I., Sablani, S. S., Powers, J. R., & Fellman, J. K. (2012). Effect of drying methods on the physical properties and microstructures of mango (Philippine ‘Carabao’var.) powder. Journal of food engineering, 111(1), 135-148. Cemeroğlu E (2009). Meyve ve Sebze İşleme Teknolojisi. Ankara, Turkey: Gıda Teknolojisi Dergisi Yayınları (in Turkish). Da Silva, D. I. S., Nogueira, G. D. R., Duzzioni, A. G., & Barrozo, M. A. S. (2013). Changes of antioxidant constituents in pineapple (Ananas comosus) residue during drying process. Industrial Crops and Products, 50, 557–562. Maskan, M. (2001). Drying, shrinkage and rehydration characteristics of kiwifruits during hot air and microwave drying. Journal of food engineering, 48(2), 177-182. Parikh, D. M. (2015). Vacuum drying: basics and application. Chemical Engineering, 122(4), 48-54. Ramallo & Mascheroni (2012). Quality evaluation of pineapple fruit during drying process. Food and Bioproducts Processing, 90, 275–283. SAS. (1999). SAS Ins. Inc., Cary, NC, USA. Proprietary Software. Release 8.2 (TS2MO). Singh, S., Raina, C. S., Bawa, A. S., & Saxena, D. C. (2006). Effect of pretreatments on drying and rehydration kinetics and color of sweet potato slices. Drying Technology, 24(11), 1487-1494.