Skim milk and garlic were purchased from the local market, and Starter Culture (YC-087, Cher. Hansen, inc., Milwaukee, WI), Rennet (Maxiren 180, 180 IMCU∙mL⁻¹, DSM Food Specialties, Delft, Netherlands), Calcium Chloride, Sodium Chloride were supplied by a local supplier of Dinajpur. All the materials and chemicals used were analytical grade.

The reconstituted milk was made with a 1:8 milk powder to water ratio (DMMPS-14). 50 g of milk powder was dissolved in 400 ml water to make reconstituted milk. A magnetic stirrer was used to stir the milk for 20 minutes to ensure appropriate dilution. The milk was then pasteurized (for 20 minutes at 72˚C). To bring the temperature of the processed milk back to normal, it was chilled with ice water.

The garlic bulb’s dry skins were removed under aseptic conditions. The garlic cloves were peeled, rinsed, and sliced with a sharp knife. After that, using an electric food grinder, the slices were crushed into a paste. The garlic paste was kept in a plastic jar at 4˚C.

Yogurt starter culture (YC-087, Cher. Hansen, Inc., Milwaukee, WI), which contained mainly L. bulgaricus and S. thermophiles, was employed in the production of cheese. The starter culture was prepared from the mother culture. For making the culture, 12 g of skim milk was diluted into 100 ml distilled water. The mix was stirred for 20 minutes in a magnetic stirrer and pasteurized at 72˚C for 20 minutes. Afterward, 0.1 g of mother culture was added to the milk. Then the milk was incubated at 35˚C for 16 hours. The prepared culture was stored at 4˚C temperature.

Chymosin (Maxiren 180, 180 IMCU∙mL⁻¹, DSM Food Specialties, Delft, Netherlands) was used for cheese manufacturing. It was added with milk sample by diluting one in ten with distilled water to aid water dispersion.

Four cheese samples were prepared by the method described by Abou-Donia [18]. In each jar, 100 ml milk was used, and garlic paste (0%, 1%, 3% & 5%) was added. For proper mixing, the milk was stirred for 20 minutes using a magnetic stirrer. Afterward, pasteurization was achieved by heating at 72˚C for 20 minutes. After cooling at room temperature (28˚C ± 2˚C), 2 g of starter culture was introduced in each sample. For ripening, the mixture was left for 30 minutes with constant stirring. Then 0.25 g CaCl₂ was added and was equilibrated for 5 minutes before incorporating 2 ml of rennet solution. The milk was coagulated in less than one hour, and cheesecloth was used to separate the whey water from the curd. After straining the curd for 40 minutes, 2% NaCl was added. Next, the cheese was cut and kept at 4˚C in the refrigerator for further analysis. Table 1 showed the basic formulation for cheese preparation and the flow diagram for cheese preparation was presented in Figure 1.

The pH of the cheese samples was determined using a standard approach developed by the Association of Official Analytical Chemists [19]. Before the whey was drained from the cheese, the pH was tested in the curd form using an electronic digital pH meter and the potentiometric approach, which involves measuring the potential difference between the sample and the electrolyte solution

present inside the electrode of the pH meter (Model HI2211 HANNA instrument, Portugal). The electrode was directly dipped into the curd form of the cheese samples. New pH 4.0 and 7.0 standard buffers were used to calibrate the pH meter on a regular basis.

Viscosity was measured using a rotational viscometer (model VR 3000, Myr). The curd was broken by stirring with a glass rod. No. 3 spindle was used, with about one-third of the spindle immersed. Each measurement was done three times at room temperature (28˚C ± 2˚C) at 100 rpm for 1 minute. The data was recorded in Pa∙s.

The Water Holding Capacity (WHC) of yogurt is defined as its ability to hold all or part of its water. The centrifugation method is used to determine the Water Holding Capacity (WHC) of a gel as a result of a strong internal force or the gel’s resistance to compaction. WHC of the samples was determined using a slightly modified centrifugation method [11]. The curd was taken in a falcon tube in principle. Three tubes were obtained from each batch of material. An equal amount of sample was obtained from each tube. The curd tube was centrifuged at 600 rpm for 10 minutes. The amount of eliminated water was determined by carefully weighing the supernatant. The resulting supernatant was weighed to determine the amount of excluded water. The water holding capacity was calculated by the equation:

WHC ( % ) = ( Y − W ) / Y × 100

where: Y = weight of the sample, W = weight of water

Syneresis, or whey ejection of acid milk gel, is required for dehydration during cheese production and can be accomplished by concentrating the gel after incubation (i.e., whey removal) by cutting, heating, or whey separation. The syneresis of the cheese samples was done by whey separation. The cheese samples were synthesized in their cured state. A thin coating of 100 g curd was placed across the surface of the Whatman No. 1 filter paper. For ten minutes, the curd was filtered under a vacuum. The liquid that flowed through the filter paper was gathered and analyzed. The percentage of syneresis was calculated as the weight of the liquid divided by the weight of the initial sample multiplied by 100 [20]. The formula can be written as:

Syneresis ( % ) = W / Y × 100

where: W = Weight of whey water, Y = Weight of sample

All the observations were performed thrice. Comparisons of means were performed by one-way Analysis of Variance (ANOVA) followed by Tukey’s test (p < 0.05). Statistical analyses were run using the Minitab 16 (State College, Pa).