Mathematical modeling of osmo assisted freeze drying process for strawberries (Fragaria vesca)
Loading...
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
The study entitled “Mathematical modeling of osmo assisted freeze drying process for
strawberries (Fragaria vesca)” was undertaken to characterize the effect of process
parameters; osmotic solution concentration (40-80 °Brix), solution to fruit ratio (4-8 STFR)
and freeze drying temperature (-20 to -40°C) on drying kinetics and quality attributes. The
treatments with -20°C freeze drying temperature required more time for drying as compared
to -30 & -40°C (2to 4 hours) to reduce the moisture content from 87.2% wb to 4.2±0.1 % wb.
The input parameters for osmo-freeze drying process for strawberry halves were optimized by
„Multiple Response Optimization‟ technique with optimum operating conditions recorded as
freeze drying time temperature: -40°C, osmotic solution concentration: 79.43° Brix and
solution to fruit ratio (STFR): 6.61. Corresponding to these values, the value of responses was
rehydration ratio: 7.150, shrinkage ratio: 0.627, colour change: 6.661, bulk density: 502.19
kg/m3, % vitamin-c retained: 71.846%, texture (hardness): 8.1871Kg-f, and overall
acceptability: 83.431%. The best fit of experimental data for osmotic dehydration was
observed in Penetration model followed by GEM model. The overall performance of the
mathematical model developed in VISUAL BASIC-6.0 for prediction of freeze drying time
for osmo-freeze drying was satisfactory (0.122-7.285 % error) and can be used for predicting
the freeze drying time for osmo-freeze drying of strawberries. The osmo-freeze and freeze
dried products packed in three types of packaging materials viz. high density polyethylene,
laminate aluminium pouches & glass jars were kept under refrigerated and ambient storage
conditions. Overall, it was concluded that osmo-freeze drying of strawberry halves at
optimized conditions of 79.43°B osmotic solution, 6.61 solution to fruit ratio (STFR) and 40°C
freeze drying temperature gave better quality product as compared to freeze drying and
can be stored for 5 and 3 months in refrigerated and ambient conditions respectively.
Description
Keywords
Citation
Sidhu, Jashandeep Singh (2021). Mathematical modeling of osmo assisted freeze drying process for strawberries (Fragaria vesca) (Unpublished Ph.D. Dissertation). Punjab Agricultural University, Ludhiana, Punjab, India.