The Effect of Walnut Addition on Chemical and Sensory Properties of Cheese Halva
Binnur Kaptan* and Sefik Kurultay
Department of Food Engineering, Namik Kemal University, Turkey
Submission: February 15, 2018;Published: May 09, 2018
*Corresponding author: Binnur Kaptan, Department of Food Engineering, Namik Kemal University, Tekirdag, Turkey, Email: email@example.com
How to cite this article: Binnur K , Sefik K. The Effect of Walnut Addition on Chemical and Sensory Properties of Cheese Halva. Nutri Food Sci Int J. 2018; 6(4): 555693. DOI: 10.19080/NFSIJ.2018.06.555693.
Cheese halva, which is produced in several regions of Turkey with different names, is one of the popular milk desserts. This dessert is made from fresh unsalted cheese and called “Cheese Halva” or cheese dessert. Sugar, flour and sometimes egg yolk are added to unsalted ewe’s or goat milk cheese according to season changes in cheese halva production. Cheese halva is sweetened by adding refined sugar or honey into the fresh unsalted cheese.
In this research, the effects of walnut addition at different proportions of ground and crushed walnut on some physicochemical properties of cheese halva were determined. Ground and crushed walnuts were added and mixed at three different ratios 5%, 10% or 15%, respectively.
Walnut is one of the significant fruit species that are gaining importance nowadays in terms of dietary fiber source, its nutrient elements and benefits for human health. Walnut, mostly consumed as snack, is the primary functional foodstuff due to its fat composition (generally oleic acid), protein, carbohydrate, fiber, vitamins (vitamin E), minerals, phytocetiroles (β-cytositerol) and antioxidant phenolic compounds. It is rich in vitamins containing thiamin, vitamin B6, folacin and iron, zinc, copper, magnesium, phosphorus and potassium . Walnut does not contain cholesterol and it is very rich in polyunsaturated fatty acids such as alphalinolenic and linoleic acid that are very important for human health . Linolenic acid inhibits inflammation, hardening and embolism of arteries by decreasing the blood pressure . It protects the body against cardiovascular diseases and diabetes by reducing cholesterol [4-8]. Walnut protects the body against some types of cancer [9,10]. Moreover, it eliminates eczema, heals wounds, protects stomach and intestine from diseases, and assists losing weight in a healthy way [11,12]. Walnut can be consumed directly as dried and is also used in the production of pastry, cake, confectionery, dessert and various dairy products (cheese, ice cream, milk puddings) to improve flavor and taste, and to enrich foods by using its flavor enhancer properties .
Cheese halva is a milk dessert. Unsalted fresh cheese obtained from ewe's or cow's milk is used for production of cheese halva with the addition of sugar, flour and sometimes egg yolk . It is a delicious traditional dessert, rich in protein, fat, minerals and vitamins and also it is a nutritious milk product. It is important to enrich flavor and aroma with different dried fruits used in the production of sugary deserts in terms of increasing the diversity of the product and bringing a new feature to the product. Furthermore, the enrichment of products with various mouth-pleasing dried fruits in the production of cheese halva and creating a new formula are important for the future value of this dessert. The most of the manufacturers have produced the Cheese halva as plain form, currently. On the other hand; walnut with a high nutritious characteristics and functional properties because of its dietary fiber source is added into the cheese halva to provide flavor diversity and functionality to the final product.
Milk used in the production of cheese halva was obtained from Namik Kemal University Zootechnics Dairy Plant. Calcium chloride (Merck), starter culture (Chr. Hansen, Denmark) and rennet used in the production of curd were commercially obtained. Sugar, flour, eggs and walnuts were supplied from local markets.
Curd production (Fresh cheese): For the curd production, milk was pasteurized at 70 °C for
15 seconds and then cooled to the fermentation temperature
(30 °C). After that, liquid rennet (1/10,000 strength) was
added to milk by diluting 1:10 ratio and hold for 90 minutes to
complete coagulation. The resulting coagulum was broken and
then whey was filtered. The obtained curd was divided into
seven equal parts at determined ratios, one being control part,
for the production of cheese halva.
Cheese halva production: For the production of cheese
halva, 1kg of curd and one egg yolk were mixed occasionally
and melted at a medium temperature. Then, 150g flour was
added and cooked for 10-15minutes until a consistent texture
was obtained. Then, 600g sugar was added to the mixture and
cooked (3-5min). Ground and crushed walnuts were added
at 5%, 10% or 15% ratios and mixed when the mixture was
allowed to cool to the room temperature. The resulting mixture
was packaged in plastics packets as 100grams portions and
then stored at +4 °C until chemical and organoleptic analyses.
Analyses for walnut: Dry matter was analyzed by
gravimetric method , fat analysis wascarried out by
Soxhelet extraction  and the amount of protein was
determined by Kjeldahl method .
Analyses for cheese halva: Dry matter was analyzed by
gravimetric method . Soxhelet extraction was applied
for analysis of fat content . Total sugar content was
determined by Luff-Schoorl method . For ash analysis, the
AOAC method was followed . The protein content of cheese
helva was calculated by Kjeldahl method . The appearance,
color, aroma and flavor characteristics of the samples were
evaluated by seven panelists based on a total of 25 points with
each characteristic being 5 points .
Statistical analysis: Simple variance analysis was
performed using SPSS statistical softwareand the Duncan test
was applied to determine whether the differences between the
groups were significant.
The results of seven cheese halva samples including one
control prepared by adding ground and crushed walnuts at
different ratios (5%, 10%, and 15%) are shown in Table 2.
For each column, different letters mean that values are statistically different (P<0.01).
As shown in Table 2, the dry matter contents of the samples
prepared with 15% crushed and ground walnuts addition
were found between 77.75% and 80.37%. As can be accepted
that the addition of walnuts at two different forms and three
different ratios made a significant difference in the dry matter
contents of samples (p<0.01).
The lowest protein content (8.964%) was found in the 5%
crushed walnut added cheese halva while the highest protein
content (11.15%) was determined in the 5% ground walnut
added cheese halva. Addition of walnut to cheese halva to
enhance flavor was an effective process changing the protein
contents at significant level (p <0.01). Significant increase was
determined in the fat content of test samples compared to that
of the control sample (p <0.01). The decreasing particle size
and increasing the surface area of walnut by grinding may
have been effective in increasing the fat content of samples.
When the test samples were compared with respect to the
ash content, the control cheese halva had 1.0367% ash, while
it was 1.2743% in the 15% ground walnut added sample.
The walnut addition affected the ash contents of samples
significantly (p <0.01). The apparent decrease in starch and
total sugar content of the cheese halva samples was observed
for the walnut added samples compared with control group.
The decreases in these characteristics were found statistically
significant with increasing walnut ratios (p <0.01).
The sensory analyses carried out with seven member
panelists group for color, appearance, texture, consistency,
flavor and aroma and overall points characteristics are shown
as mean values in Table 3. The perfect point was 5 points for
each determined parameters and also 25 points totally.
While the samples prepared with crushed walnut had lower
sensory points, cheese halva samples prepared with ground
walnuts obtained higher scores from panelists and found to
have a pleasant flavor. Especially in the taste points, crushed
walnut added samples had the lowest points because of the
high level of fat oxidation of the crushed walnut as a result of
higher surface exposure to oxygen.
In conclusion, traditional tastes like as Cheese Halva
have been consumed for ages in Turkey with different names
and processing technics. In this study, addition of crushed
or ground walnut may be thought as an alternative product
for manufacturers for serving to consumers. It increases
nutritional quality of the product and gives a stronger
aroma, which makes the product commercially attractive for