TY - JOUR
T1 - Solar drying of strawberry using polycarbonate with UV protection and polyethylene covers
T2 - Influence on anthocyanin and total phenolic content
AU - Rodríguez-Ramírez, Juan
AU - Méndez-Lagunas, Lilia Leticia
AU - López-Ortiz, Anabel
AU - Muñiz-Becerá, Sahylin
AU - Nair, Karunakaran
N1 - Publisher Copyright:
© 2021 International Solar Energy Society
PY - 2021/6
Y1 - 2021/6
N2 - Cover material of solar dryers influences on fruit properties due to the temperature and ultraviolet radiation (UV) during drying. Polyethylene (P) is the most used material for covering solar dryers. Cellular polycarbonate (CP) is a material that promotes UV protection; hence, it has recently been proposed as a covering material for greenhouse dryers. However, it is unknown whether CP cover will have any effect on bioactive compounds of foods treated by solar drying. Especially, if CP has advantages in preserving sensitive compounds compared to traditional materials as P. In this work the effect of CP and P covers on anthocyanins (TA) and total phenolic compounds (TPC) of strawberries during solar drying was evaluated. Open sun drying was used as a reference. Drying temperature, solar radiation, external and internal UV radiation was measured. The results indicated that the drying temperature and UV radiation influenced the moisture content and bioactive compounds. Direct radiation increased the drying temperature and reduced the final moisture content, while the partial incidence of UV radiation in the dried samples with P covers favored the remaining 40.7% of TA and 42.5% of TPC. With CP covers, where the ultraviolet radiation was zero, the 15.5% of TA and 14.4% of TPC were retained. Activation energy indicated that bioactives were more stable in the solar dryer with P and transparent cellular polycarbonate covers, demonstrated that they can be used as coatings in solar dryers destined for drying fruits, producing high-quality dehydrated products and efficient solar drying processes.
AB - Cover material of solar dryers influences on fruit properties due to the temperature and ultraviolet radiation (UV) during drying. Polyethylene (P) is the most used material for covering solar dryers. Cellular polycarbonate (CP) is a material that promotes UV protection; hence, it has recently been proposed as a covering material for greenhouse dryers. However, it is unknown whether CP cover will have any effect on bioactive compounds of foods treated by solar drying. Especially, if CP has advantages in preserving sensitive compounds compared to traditional materials as P. In this work the effect of CP and P covers on anthocyanins (TA) and total phenolic compounds (TPC) of strawberries during solar drying was evaluated. Open sun drying was used as a reference. Drying temperature, solar radiation, external and internal UV radiation was measured. The results indicated that the drying temperature and UV radiation influenced the moisture content and bioactive compounds. Direct radiation increased the drying temperature and reduced the final moisture content, while the partial incidence of UV radiation in the dried samples with P covers favored the remaining 40.7% of TA and 42.5% of TPC. With CP covers, where the ultraviolet radiation was zero, the 15.5% of TA and 14.4% of TPC were retained. Activation energy indicated that bioactives were more stable in the solar dryer with P and transparent cellular polycarbonate covers, demonstrated that they can be used as coatings in solar dryers destined for drying fruits, producing high-quality dehydrated products and efficient solar drying processes.
KW - Bioactive compounds
KW - Cellular polycarbonate
KW - Covers
KW - Polyethylene
UR - http://www.scopus.com/inward/record.url?scp=85104910707&partnerID=8YFLogxK
U2 - 10.1016/j.solener.2021.04.025
DO - 10.1016/j.solener.2021.04.025
M3 - Artículo
AN - SCOPUS:85104910707
SN - 0038-092X
VL - 221
SP - 120
EP - 130
JO - Solar Energy
JF - Solar Energy
ER -