Extension of shelf-life of paneer by microwave treatment
Abstract
The study was conducted to enhance the shelf life of paneer with
microwave treatment. Paneer was cut into slices approximately equal size and weight
(120-150 gms.) treated at different microwave power level for different time. The
appropriate time and power level combination was selected on the basis of sensory
attributes. Immediately after treatment samples were packed in multilayered
polyethylene (PE) pouches under vacuum and polystyrene (PS) cups covered with
aluminium foil were placed at room temperature as well as refrigeration temperature till
the spoilage of samples. Samples were analyzed for their sensory, phsico-chemical
properties and microbiological quality at fortnight interval. The result of present study
indicated that microwave power & time 80W for 8 minutes (T1) and at 800W for 2
minutes (T2) were found suitable for the treatment of paneer samples. T1 & T2 samples
had shelf life of less than 15 days irrespective of packaging material and storage
condition except T1 had a shelf life of 15 days when packed in PE pouches, stored at
refrigeration temperature and T2 had shelf-life of 60 days under similar conditions of
packaging and storage. At 0 day judges “liked very much” T1 sample while T2 sample
was “liked moderately”, T2 sample packed in PE pouches and stored at refrigeration
temperature was “liked slightly” by the judges at 60th day of storage. pH of T1 and T2
sample had shown the decreasing trend irrespective of packaging and storage condition
except under refrigeration temperature T2 sample packed in PE pouches had shown
increasing trend in pH up to 45 days of storage and thereafter it had decreasing trend
and acidity had shown reverse trend of it. Tyrosine and FFA value had shown increasing
trend in both the samples during the entire period of storage irrespective of packaging
material and storage conditions.
Bacteriological analysis reveled that at 0 day of storage no spore former
count were observed in any of the sample. Whereas later on at 15th day of storage in T1
and T2 samples packed in PE pouches and PS cups, stored at room temperature
number were 210, 230 & 180, 190 respectively while under refrigeration storage PS
cups sample had the number 180 & 160 respectively at 15th day of storage. T1 PE
pouches packed sample had bacterial number was 100 at 15th day while T2 had a
count of about log 4 at the end of storage. It is concluded from the study the T1 paneer
sample packed in PE pouches and stored at refrigeration could be stored 15 days and
T2 sample could be stored up to 60 days, while these samples when kept at room
temperature could not be stored even up to 15 days. Samples packed in PS cups were
spoiled before 15 days of storage irrespective of storage condition, treatment and
packaging material.
Description
Keywords
Paneer, Shelf life, Microwave treatment