Insights on Manufacturing Process of Paneer

 Paneer is an unaged variety of cheese, classified as a traditional Indian dairy product and is known to be one of the most popular party foods among vegetarians.  Indian paneer is the fresh and non-melting cheese, which is prepared by curdling of milk using some citric acid or any acidic vegetable liquid. The curdled milk is also called as chena or cottage cheese. 

 Paneer is obtained by the acid and heat coagulation of milk at a high temperature. Paneer contains large structural aggregates of proteins formed during the coagulation of milk in which milk fat and other colloidal and soluble milk solids are entrained with whey.

According to FSSR, paneer shall not contain more than 70% moisture and the fat content should not be less than 50% of dry matter. Good quality paneer is characterized by a white color, sweet, mildly acidic flavor, spongy body, and a closely knit texture. Paneer has a high nutritional profile as it retains about 90% of the fat and protein, 50% of the minerals, and 10% of the lactose of the original milk. The proximate composition of paneer is 54% moisture, 17.5% proteins, 25% fat, 2% lactose, and 1.5% minerals.

                                                                           

                                              

Method of Manufacture -

Traditional method of manufacture:

Buffalo milk is boiled in a bigger iron vessel and a small portion of this is transferred to a smaller vessel. The coagulant (usually sour whey) is added to hot milk and stirred with a ladle till coagulation is completed. The contents of the vessel are emptied over a piece of coarse cloth to drain off whey. The whole process is repeated till all the milk is coagulated. The curd is collected after draining the whey and pressed to remove more whey. Finally, product is then dipped in chilled water.

Commercial Manufacturing of Paneer:

Commercial production of paneer involves 6 process steps and they are as follows –

Step 1: Milk Standardization

For commercial manufacture of paneer buffalo milk is standardized to 5.8% fat having 9.5% SNF (standardize the buffalo milk to a fat: SNF ratio of 1:1.65).

Step 2: Heat Treatment:

After standardization of milk, it is heated to 90°C without holding (or 82°C with 5 minutes holding) in a jacketed closed vessel known as Paneer Vat. Then milk is allowed to cool down to 70°C. Heat treatment of milk causes destruction of microorganisms, denatures whey proteins and retards colloidal calcium phosphate solubility.

Step 3: Coagulation and Draining of Whey

Coagulation is done at about 70°C by slowly pouring 1% hot (70°C) citric acid solution with constant stirring till a clean whey is separated (pH 5.30 to 5.35) and coagulum is allowed to settle for 5 minutes, after which the whey is drained off.

Step 4: Hooping

 The curd so obtained is filled into hoops lined with cloth.

Step 5: Pressing

Pressure is applied on top of the hoop at a rate of 0.5 to 1kg/cm2. The surface of hoops must contain holes to facilitate whey expulsion. Good quality product can be prepared by pressing for around 15 min.

Fig. Paneer Press Machine

Step 6: Dipping in Chilled Water

The pressed blocks of paneer are removed from the hoops and immersed in chilled water for 2-3 hrs. The chilled paneer is then removed from water to drain out. This step assists in developing texture and speeds up the cooling process. The water used for chilling should be of good bacteriological quality.

Step 7: Packing

Finally, paneer blocks are wrapped in parchment paper / polyethylene bags and placed in cold room at about 5 to 10°C.

Factors Affecting Quality of Paneer -

·         Type of milk

Paneer prepared from buffalo milk will have desirable frying properties, body and texture as compared to cow milk. The cow milk paneer is too soft, weak, and fragile and during cooking it tend to disintegrate. However, cow milk and buffalo milk at 50:50 yields better product than cow milk. Paneer made from skim milk has chewy, rubbery, and hard body.

·         Quality of Milk

To obtain paneer of good quality, the milk must be fresh and free from off flavor. Growth of psychotropic organisms should be minimized to restrict the off-flavor development. Acidic milk having a titratable acidity of more than 0.20% lactic acid yields a product of inferior quality. The milk with COB positive and low acidity (sweet curdling) is not suitable for paneer making. Paneer made from such milk has weak body and texture, more moisture, acidic smell and not safe for human consumption.

·         Type and Strength of Coagulant

Citric acid is generally used as a coagulant. Lemon or lime juice or vinegar imparts a typical flavor to the product. The concentration of citric acid used for best results is 1%. A higher concentration may lead to a harder product with a higher loss of solids. For coagulating 1 kg of milk, about 2–2.5 g of food-grade citric acid is used. Naturally, soured whey cultured with Lb. acidophilus added at 2% and incubated overnight at 37°C reduces the requirement of citric acid and increases the recovery of solids without loss of quality.

·         Heat Treatment of Milk

The objective of heating the milk is to prepare the milk for rapid iso-electric precipitation, control the moisture content, develop typical body and texture, create conditions conducive to the destruction of pathogenic and other microflora present in milk and ensure safety as well as keeping quality of the final product. The milk is heated to 90°C without holding or 82°C for 5 minutes to maximize the total solids recovery. Whey proteins especially ß-lactoglobulin and a-lactalbumin form a complex with Қ-casein and retain with the curd thus increase the yield of the product. The high heat treatment imparts desirable cooked flavor by controlled liberation of sulfhydryl compounds.

·         Coagulation Temperature

It influences the moisture content of the paneer, an increase in temperature from 60° C to 86° C decreases the moisture in paneer from 59 to 49%. At 70° C, paneer has the best organoleptic and frying quality in terms of shape retention, softness, and integrity.

·         pH of Coagulation

The optimum pH of coagulation of milk at 70°C is 5.30-5.35. The moisture retention in paneer decreases with the fall in pH and consequently the yield also decreases. At pH more than 5.35 the paneer is incredibly soft with fragile and crumbly body texture. Optimum pH when cow milk is used for paneer preparation is 5.2.

Paneer can be made from both cow and buffalo milk. Cow milk yields an inferior product in terms of body and texture. It is criticized to be too soft, weak and fragile and unsuitable for frying and cooking. Buffalo milk contains considerably higher level of casein and minerals particularly calcium and phosphorous, which tends to produce hard and rubbery body while cow milk produces soft and mellow characteristics. By replacing one third of buffalo milk with cow milk, a good quality paneer can be made. Buffalo milk paneer retains higher fat, protein and ash content and lactose as compared to cow milk paneer. To make paneer exclusively from cow milk, certain modifications in the conventional procedure have to be made. Addition of calcium chloride at the rate of 0.08 to 0.1% to milk helps in getting a compact, sliceable, firm and cohesive body and closely knit texture. A higher temperature of coagulation (85°-90°C) with coagulation of milk at pH 5.20 to 5.25 helps in producing good quality paneer from cow milk. However, at this pH of coagulation, moisture, yield and solids recovery are less.

Paneer represents a variety of Indian soft cheese, which is used as a base material for the preparation of many culinary dishes and is highly nutritious and wholesome. Most of the paneer is produced in unorganized sector in exceedingly small quantities using traditional methods. Reluctance to use modern technological processes has hampered the organized production, profitability, and export performance of paneer. Therefore, due to increasing demand for paneer, advancement is required in the manufacturing of paneer which will result in increased yield of paneer, reduction in production cost, and increase in shelf life of paneer as well as production of new varieties of paneer for health-conscious people.