Physicochemical Properties of Guava Snacks as Affected by Drying Technology

Yuri M Leiton-Ramírez,Alfredo Ayala-Aponte,Claudia I Ochoa-Martínez

doi:10.3390/pr8010106

Abstract

Guava is widely consumed because of its agro-industrial use, and its antioxidant properties attributed to vitamin C and carotenoids content. However, it has a short shelf life. Guava has been dried by atomization, fluidized bed, lyophilization (FD) and convective drying (CD). CD requires long operation times and the product characteristics are not desirable. In contrast, FD produces high quality products, but requires long processing times, high energy consumption and high operation costs. As an alternative, the Refractance Window® (RW) drying is relatively simple and cheap technique. The objective of this study was to compare the effect of CD, FD and RW techniques, on the moisture content, water activity, color, porosity, volume change, vitamin C and carotenoids content in guava samples. The samples dried by RW required less time to reduce the moisture content and exhibited smaller changes in color than CD or FD. There were greater losses of carotenoids and vitamin C when drying by CD whereas RW had similar losses than FD. Lyophilized products exhibited minor change in volume and greater porosity. RW results in better retention of properties, compared with other drying techniques. Based on this, RW is a promising technique for the development of guava snacks.

Highlights

Pink guava (Psidium guajava L.), which belong to the Myrtaceae family, is a favorite fruit in tropical and hot subtropical zones and is becoming increasingly popular in European and North American markets, because of its high potential for agro-industrial use, and its known antioxidant properties mainly attributed to vitamin C and carotenoids content [1,2]
The decrease in water content using Refractance Window® (RW) was achieved in less time than the convective drying (CD) and FD methods; 3.1
The decrease of 12 in water content using RW was achieved in less time than the CD and FD methods; with5RW, a moisture content of 0.040 ± 0.002 g water/g db was achieved in 76 min, whereas the same moisture content achieved in 107

Summary

Introduction

Pink guava (Psidium guajava L.), which belong to the Myrtaceae family, is a favorite fruit in tropical and hot subtropical zones and is becoming increasingly popular in European and North American markets, because of its high potential for agro-industrial use, and its known antioxidant properties mainly attributed to vitamin C and carotenoids content [1,2]. The high levels of these compounds could suggest their relevance in boosting the immune system as well as in cancer prevention This fruit is used in different processed products such as nectars, juices, preserves, jams, syrups and beverages; dehydrated guava (as snack or as an ingredient for other food products) is not as common as the other products in the market. Guava has been dried by various methods such as atomization [6], oven-drying [1,7], fluidized bed drying [8], heat pump dryer [9], lyophilization [1,2,9,10], cast-tape drying [11], and hot air drying [9,12].

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Conclusion