MANUFACTURE OF PROCESSED CHEESE USING RENNET CURD FROM ULTRAFILTRATION RETENTATE
Loading...
Date
2022
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ICAR-NDRI, KARNAL
Abstract
The cheese market in India reached a value of INR 44.8 billion in 2020 and expected to grow
annually by 24.80 % during 2021-2026. Processed cheese has been one of the most dynamically
growing segments of the food industry and the most consumed cheese variety in India. It
contributes approximately 45 % of the total cheese market. Over the past ten years, there has been
a sharp growth in processed cheese production, consumption and trade due to its more enticing
flavour profile and versatility at much more economical price than other types of cheese available
in the market. Natural cheese being major ingredient in manufacturing of processed cheese
involves high cost during production and ripening which reflects in the final price of processed
cheese produced. As a new approach, the present study was done to manufacture processed cheese
using rennet curd obtained from ultrafiltration (UF) retentate. UF of skim milk resulted in
reduction in flux with a mean flux value of 0.46 kg/m2min. Processed cheese was prepared using
rennet curd (moisture 59.75±0.31 % w/w; protein 35.09±0.43 % w/w), butter (fat 84.50±0.50 %
w/w), NaCl (@ 2 %) and different emulsifying salts (@ 3 %). Twenty one processed cheese
samples from seven different emulsifying salts (in individual and in blend of binary or ternary)
with three different extents of hydration (0, 60 & 120 min) were prepared and the optimization
was done in comparison to the control processed cheese (CPC) prepared from natural Cheddar
cheese. Processed cheese prepared from rennet curd (RPC) was having proximate composition
comparable to CPC with respect to moisture, fat and protein. The prepared slurry was analysed for
pH and % soluble calcium (SC) and it was found that type of ES and hydration time had significant
(P<0.05) effect on slurry pH and SC. Hydration resulted in increased SC in case of Salt A, blend
of Salt A with Salt B and in the blend of Salt B and Salt C, but for other salts, it reduced upon
hydration. The change in SC resulted in significant (P<0.05) changes in textural, functional and
rheological properties of RPC. Increase in SC resulted in increase in hardness and melt properties
(meltability and flowability) of RPC prepared from Salt A, but in the case of phosphate-based ES,
decrease in SC upon hydration resulted in reduction in hardness and increased melt properties due
to improper emulsification of fat. The type of ES and hydration affected the rheological parameters
and were in agreement with meltability (damping factor) and hardness values (storage and loss
modulus). CPC had less hardness (41.20±1.58 N) and more meltability (6.57±0.73) as compared
to all RPCs prepared. The Salt A at 60 min hydration had melt properties close to CPC and thus
was selected as optimised cheese matrix for flavour incorporation at different levels of enzyme
modified cheese (EMC). Confocal microscopy confirmed the improved fat emulsification in RPC
prepared from Salt A at 60 min hydration as compared to unhydrated sample (Salt A-0) and CPC.
Optimised processed cheese incorporated with 3 % EMC along with CPC were analysed during
storage of 35 days for physico-chemical, textural, functional, rheological and colour values at an
interval of 7 days at 5±1 °C. Storage of both samples resulted in significant (P<0.05) changes in
physico-chemical properties viz. moisture, pH, acidity, water activity, tyrosine value, degree of
hydrolysis, acid degree value and TBA value. Sensorial, textural, functional, rheological, colour
values and microbiological quality of cheese samples were affected during storage period.
Optimised processed cheese can be produced at 7.84 % lesser cost as compared to control cheese.
Hence in comparison with conventional processed cheese, UF rennet curd can be selected as a
replacement for matured cheese to manufacture processed cheese at reduced cost with better
stability.