Effect of Canning/Thermal Processing on Quality Characteristics of Yakhni
Sajad A Rather, FA Masoodi*, SM Wani and Adil Gani,
Department of Food Science and Technology, University of Kashmir, India
Submission: February 20, 2017; Published: March 23, 2017
*Corresponding author: FA Masoodi, Department of Food Science and Technology, University of Kashmir, Srinagar-190006, India,
Tel:+91-9419135876, Email: [email protected]
How to cite this article: Sajad A R, F Masoodi, S Wani , Adil G .Effect of Canning/Thermal Processing on Quality Characteristics of Yakhni. Dairy and Vet Sci J. 2017; 1(4): 555569. DOI: 10.19080/JDVS.2017.01.555569
The study was conducted to analyze the effect of goshtaba products with varying levels of fat and different gums and canning/thermal processing on the proximate composition and microbial stability of yakhni (gravy). The results indicated that non-significant difference was observed in moisture, protein, fat and ash contents in all formulations after canning (P>0.05), except yakhni from high fat control formulation which showed significantly higher fat content (P<0.05). Incorporation of different gums in goshtaba products showed non-significant effect on proximate of yakhni formulations (P>0.05). Microbial evaluation exhibited that after heat processing no viable microbes was recovered from any of the yakhni formulations. Thus all yakhni formulations were commercially sterile.
The state of Jammu and Kashmir in India is widely known for wazwan, which is a multi-course meal in Kashmiri cuisine. The preparation of wazwan is considered an art and a point of pride in Kashmiri culture and identity. Yakhni forms the essential component of Kashmiri wazwan. Yakhni is prepared from curd, water, hydrogenated vegetable oil, spices and condiments along with the meat balls (Goshtaba) or mutton pieces. This recipe has mouth-watering flavours that can tempt any one and is usually served with steamed rice. Aromatic spices included fennel seeds, cinnamon, cardamom, cloves etc. are added which are responsible for unique taste and flavour of yakhni.
Dairy and meat products when stored at room temperature can serve as an excellent medium for growth of microorganisms, since they are a good source of amino acids and nitrogen . When these microorganisms multiply, they produce toxins that are hazardous and even lethal to humans . Indian dairy and meat processing is focusing on export, looking for unique shelf stable products for national and international markets. High perishability of yakhni is a serious problem for its commercialization. Thus the preservation alternative that may enhance the shelf life of this product at ambient temperature is important so that this good protein source can be offered to other regions of the country and to promote its export potential. There are many methods of production, thermal processing is one the promising method of processing food products .
Thermal processing has been widely used in food processing to produce microbiologically safe products having acceptable eating quality. Commercial thermal processing ensures a reduction or inactivation of spore-forming microorganisms sufficient to guarantee commercial sterility. Canning is a way of value addition of food products that can be served to consumers for more than 2 years, and it continues to be the most preferred and convenient technique of preservation to produce shelf stable products that can be stored at ambient temperatures . The objective of this study was to evaluate the effect of canning on proximate composition and microbial stability of yakhni a traditional curd and meat based product of Jammu and Kashmir, India.
Fresh boneless mutton and mutton fat from three different male sheep were purchased on three different occasions from a local butcher at Hazratbal Srinagar, India. Non-meat ingredients, salt, fresh curd from cow’s milk, oil and spices were procured from the local market. Guar gum used in this study was procured from Hi-Media Pvt. Ltd., Mumbai India.
Formulation of yakhni Lean meat and mutton fat were initially ground separately in a mincer (SIRMAN, TC 22, Italy) through an 8-mm plate and divided into five parts for various formulations, which differed in composition with respect to fat
content and guar gum level. Each treatment, which comprised of
a formulation with a specific composition in terms of fat and gum
level, was triplicated in each batch. The first formulation was
used as high (regular) fat control and fat content was adjusted
to 20% by the addition of mutton fat. The second formulation
was used as low fat control and fat content was adjusted to
10% by the addition of mutton fat. The other formulations
were supplemented with various levels of guar gum 0.5%,
1%, and 1.5% and fat content was adjusted to 10% with the
addition of mutton fat. After addition of the fat replacers the
emulsion formulations were first subjected to manual mixing
and then homogenized in a blender for 2 min to ensure uniform
distribution of the fat replacer.
The remaining non-meat ingredients (salt 2.5%, black
cardamom seeds 0.2% and cumin 0.1%) were then added to the
mixture and mixed for eight additional min to make homogenous
viscoelastic like mass. The mixtures were reground separately
in a mincer (SIRMAN, TC 22, Italy) through a 6-mm plate. The
temperature of emulsion was maintained below 10 °C during
mincing by using all the relevant materials under chilled
conditions and addition of chilled water. Meat balls weighing 50-
60g and diameter of about 60mm were made from the material.
The balls were rolled between palms to achieve their sphericity.
The meat balls from each batch were then processed in curd
(gravy) separately to get goshtaba and yakhni as the finished
Yakhni is the gravy, in which meat balls are processed (Table
1). For preparing yakhni two parts of fresh curd was homogenized
with one part of water with a stirrer, transferred to a thick
bottomed stainless steel vessel and heated rapidly on a gas stove
for 10-15 minutes. During heating curd was constantly stirred
until it reached the boiling point. Hydrogenated vegetable oil was
added to it and boiling continued for 10-15 minutes. Then garlic
paste was added followed by other spices i.e., black cardamom,
green cardamom, cinnamon, cloves, dried ginger powder and aniseed powder, respectively. Fried onion paste was added at the
end. Boiling was continued until the added oil floated back. At
this stage, the remaining water was added and yakhni was cooked
further for 10-15 minutes, to obtain a desirable consistency. Salt
was added towards the end of cooking. The meat balls were then
transferred to the boiling yakhni and cooked for 30min.
Canning/thermal processing of yakhni immediately after the
preparation of product four meat balls about 200g was packed
into washed and cleaned tin cans. The hot gravy (yakhni) at
80±5 °C was then added to each can and lid was applied by single
seaming operation. During can filling care was taken to avoid the
gravy (yakhni) from contaminating the sealing area of the cans.
Head space of about 10% was maintained from the can contents
to allow the contents to boil during processing. The cans were
exhausted under steam in an exhaust box (Bajaj India, AJAX) at
100 °C for 10min and immediately double seamed in a double
seaming machine. Thermal processing was then carried out in
an over pressure autoclave (Yorco Sales Ltd., YSI-402D) at 121
°C and 15 psi pressure for about 35 minutes. The cans were
cooled immediately by spraying chilled potable water under
pressure to a specified temperature of 38 °C, so as to prevent
the proliferation of thermophiles and the product from getting
over cooked. The cans were then air dried, labeled and kept at
ambient temperature for two weeks for conditioning before
analysis of yakhni.
Total plate count, coliform count, anaerobic plate count,
clostridium count and yeast and mould counts of the yakhni
samples were determined by standard methods. Readymade
media from Hi-Media Laboratories (P) Ltd., Mumbai were used
for the enumeration of different microbes.
All tests were done at least three times for each experimental
condition and mean values are reported. Data were analyzed
using general linear model (GLM) procedure of SPSS Statistics (v.
16, Inc., Chicago, IL) for two-way analyses of variance (ANOVA) as
a function of formulation and storage period. Duncan’s multiple
range test (P<0.05) was used to determine the differences
between means. The statistical analysis for each parameter
combines the data from three batches.
Consumers are interesting in the chemical composition of
food product and are one of the most important criteria which
consumers look for when purchasing the food product. Thus
the changes in moisture, protein, fat and ash contents of yakhni during canning were monitored and the results are presented
in Table 2. After canning the moisture content of yakhni from
control formulations (YHFC, YLFC) increased slightly. However
the yakhni from low fat formulations with gums exhibited lower
values compared to their pre-canned counterparts (p>0.05).
The slight decrease in moisture content of yakhni from low fat
formulations after canning could be attributed to the absorption
of moisture by the product incorporated with gums. Comparison
of different yakhni samples reveals that the samples from control
formulations (YHFC, YLFC) exhibited slightly higher moisture
content compared to the samples from low fat formulations
(p>0.05). This slight variation in moisture content might be
attributed to the higher protein oxidation in control goshtaba
formulations resulting in higher release of water which is
added during emulsion preparation, thus contributing to higher
moisture content of yakhni (filling medium). The yakhni from
control formulations (YHFC, YLFC) exhibited slight decrease
while that from the low fat formulations exhibited slight increase
in protein content following the canning process (p>0.05).
Changes in protein content of yakhni from different goshtaba
products could be attributed to the changes in moisture content. The protein content of yakhni from low fat products was higher
compared to the yakhni from control goshtaba and increased
slightly with the increasing concentration of gums. This higher
protein content might be due to the more water retained by low
fat goshtaba products resulting in greater protein content of
their respective gravy (yakhni) samples compared to the control
formulations. After canning the yakhni from high fat goshtaba
exhibited significant increase in fat content (p<0.05), whereas
yakhni from all low fat goshtaba products exhibited slight
non-significant increase compared to the pre-canned samples (p>0.05). A proportion of fat loss by goshtaba products into the
filling medium (yakhni) during thermal processing might have
contributed to the slight increase in fat content of yakhni after
canning. Comparison of different samples reveals that yakhni
from high fat control exhibited significantly higher fat content
during the entire storage period than the yakhni from low fat
goshtaba products (p<0.05). Though there was no variation in
the initial composition of different yakhni samples, the higher fat
content of yakhni from high fat goshtaba might be due to migration
of fat from main product into its surrounding medium during
thermal processing. Because the higher initial fat content in high
fat goshtaba can create large fat pools, which helps fat to migrate
out of the inner to the outer part of the goshtaba and resulting
in higher fat loss into filling medium (yakhni) during thermal
processing. After canning the yakhni from control goshtaba
products exhibited slight increase in ash content, whereas the
yakhni from low fat goshtaba products showed decrease in
values, however the differences were non-significant (p>0.05).
This variability may be due to the changes in composition of the
samples during thermal processing. Ash content is a measure of
minerals in a food commodity. The slight increase in ash content
of the yakhni samples from low fat goshtaba products might
be attributed to the salt content increase during canning due
to penetration of moisture from yakhni (filling medium) into
goshtaba products containing gums. Comparison of different
samples reveals that, the yakhni from low fat goshtaba products
incorporated with gums exhibited slight higher values compared
to the yakhni from control formulations (p>0.05). This slight
variation in ash content might be attributed to the variability in
fat and moisture loss into yakhni from goshtaba products during
thermal processing and subsequent storage.
All values are mean ± standard deviation. Means in the same column with different superscripts differ significantly: *P<0.05. Means with different
superscripts in the same row indicate significant difference: *P<0.05.
YHFC: Yakhni of goshtaba with fat (20%); YLFC: Yakhni of goshtaba with fat (10%); YGG1: Yakhni of goshtaba with fat (10%)+guar gum (0.5%); YGG2:
Yakhni of goshtaba with fat (10%)+guar gum (1.0%); YGG3: Yakhni of goshtaba with fat (10%)+guar gum (1.5%); YXG1: Yakhni of goshtaba with fat
(10%)+xanthan gum (0.5%); YXG2: Yakhni of goshtaba with fat (10%)+xanthan gum (1.0%); YXG3: Yakhni of goshtaba with fat (10%)+xanthan gum
(1.5%); YGXG1: Yakhni of goshtaba with fat (10%)+guar/xanthan gum (0.5%); YGXG2: Yakhni of goshtaba with fat (10%)+guar/xanthan gum (1.0%);
YGXG3: Yakhni of goshtaba with fat (10%)+guar/xanthan gum (1.5%).
The canned yakhni samples were analyzed for the presence
of aerobic or anaerobic mesophilic and thermophilic bacteria,
yeast and mould counts immediately after canning. The results
indicated that microbial counts including total plate count, total
coliform count, anaerobic plate count, total clostridium count,
yeast and mould counts were not detected in any yakhni sample
after processing. The absence of microbial counts was because
of the severity of thermal treatment during canning, thus all
samples were commercially sterile. The thermal treatment was
therefore, adequate to achieve commercial sterility and hence
the safety of product. Our results were in accordance with earlier
researchers  who studied UHT processed milk and found
commercial sterility after thermal processing. Similar results
were also observed for retort processed rose flavoured milk
during 90 days storage period .
The results of this study concluded that yakhni can be
preserved by thermal processing without any detrimental
effects to the proximate composition which is important quality
attribute affecting the consumer acceptability of food products.
The results of microbial evaluation after canning revealed that microbial counts were not detected in any sample immediately
after canning, thus indicate the thermal sterility of the product.