Fresh cow’s milk was procured from the students experimental dairy plant (SEDP).

The milk was standardized to 4.5% fat and 8.5% MSNF by adding calculated amount of

fresh cream and or skim milk powder.

3.1.2 Cream

Fresh cow milk was subjected to centrifugal separation using Alfa Laval cream

separator (AE 108) at SEDP. Cream thus obtained testing 65% fat was used for

standardization of milk fat

3.1.3 Skim milk powder (SMP)

Amul spray dried SMP (Sagar brand) was used to standardize the MSNF of milk

during the product development.

3.1.4 Citric acid

Food grade citric acid supplied by E’Merck (India) Ltd, was used as a milk coagulant

in the preparation of paneer spread.

3.1.5 Tri sodium citrate

AR grade Trisodium citrate supplied by E’Merck (India) Ltd, was used as an

emulsifying salt for paneer spread preparation.

3.1.6 Whey protein concentrate (WPC)

WPC was procured from Mahan proteins Ltd Mathura (UP). The specifications of

WPC is as follows:

Physicochemical characteristics

Colour Cr.white

Taste Bland

Bulk density ( gm/ml) 0.41

Sediment, ADPI Disc B

Insolubility Index, ml 1.2

Moisture 3.80

pH( 10 %w/v solution) 6.62

Protein % (on dry matter) 69.25

Fat % as such 4.99

Total minerals % as such 4.57

Microbiological characteristics

Total plate count per gm 700

Coliforms/0.1gm -Ve

Salmonella/100g -Ve

Yeast & mould/gm 10

3.1.7 Sodium caseinate

Mahan proteins Ltd. Mathura (UP) supplied sodium caseinate having the

following specifications

Physicochemical characteristics

Colour Cr.white

Taste Bland

Sediment, ADPI Disc B

Moisture % 4.0

pH (10% w/v solution) 7.02

Protein % on dry matter 88.10

Fat % 2.33

Total minerals % 4.75

3.1.8 Other ingredients

Soy flour, soy oil, sunflower oil, corn oil and groundnut oil. Flavour enhancers

such as Pepper, cinnamon, clove and cheddar cheese were procured from local market

3.1. 9 Chakka

Chakka was prepared according to Rao (1978). The standardized milk was heated

to 85°C for 15 minutes. After cooling to room temperature, the milk was inoculated with

a culture of streptococcus lactis at 2% level, mixed thoroughly then incubated at 30°C for

16-18 hours (generally overnight). The curd obtained was taken in to a clean muslin cloth

and hung from a stand for 8 hours to drain out whey. Thereafter, the muslin cloth was

removed from a stand and remaining semisolid matter called ‘chakka’ was removed from

the cloth to sterile container and used at 20, 30 and 40 per cent levels in the preparation

of paneer spread.

3.1.9 Packaging materials.

The packaging material used for paneer spread for storage studies consisted of

Polylyethyleneterapthalate/polyethylene/metellosin/polyethylene

(PET/PE/Mettalosine/PE)

3.1.11 EQUIPMENTS

3.1.11.1 Vacuum packaging machine

Vacuum packaging machine with following specifications were used in this study

and the schematic of the same is given in the Fig -1:

Type : Batch

Make : Reepack–Packaging machinery supplies,

Denmark

Model : RV 50

Power : 230 V AC (50/60Hz)

Dimension : 47.3 x 39 x 40 cm (L x W x H)

Material : AISI-304 Stainless Steel

Weight : 50.0 kg

Chamber width : 32.5 cm

Chamber depth : 33.0 cm

Chamber height : 16.0 cm

Sealing bar length : 31.0 cm

Vacuum pump : 6 m3/hr

Power consumption : 350 watt

Programmers to record : 9, standard

Super vacuum setting : Standard

Quick vacuum stop : Standard

Sever-seam sealing : Standard

Inert gas flushing system : Optional

Slanted plate : Optional

Fig. 1. Vacuum packaging machine

1. Vacuum packaging machine: The machine is programmed using the control

panel in the front as mentioned below:

i) First select “Vacuum” and set it to 100% by using increase or decrease

button on the control panel

ii) Select “Seal” option and set it to 4.5 s and

iv) Ensure the machine is connected to power supply

Now, keep the package containing paneer spread and insert the mouth of the

package in to the “nozzle” provided inside the chamber of vacuum packaging

machine. Close the top cover. The machine starts and the following operations are

carried out automatically:

Aspiration: The pump creates vacuum as per set value by removing air from chamber and

package containing paneer spread

Sealing: Immediately after creation of the vacuum, the sealing bars hermetically seal the

pouch.

Air reentry: The cover reopens automatically and allows the air to the re-enter in to the

chamber.

3.1.11.2 Microwave processor

The continuous type Microwave processor with the following specification was

used to process the paneer spread:

Type : Microwave powered continuous processor

Make : M/s Microwave products (India) Ltd

Model : MPCD/005/2003-04

Input power : 6 kW

No. of magnetrons :3

Microwave power : 3 kW

Power of each magnetron : 1 kW

Microwave frequency : 2450 MHz

Power supply : 415 V AC, 3 phase

Conveyor type : Teflon belt

Length of conveyor : 3 m

Speed of conveyor : 0-6 m/min

Dimension of equipment : 3.2 x 0.6 x 1.4 m (L x W x H)

Dimension of cavity : 2 x 0.2 x 0.9 m (L x W x H), with suitable

flanges at both ends

Cavity material : Stainless steel-316

Material of construction : AISI-304 Stainless steel

The continuous microwave processor consists of following components. The

schematics of the system is given in Fig – 2

1. Microwave power generator/processor

2. Conveyor mechanism

3. Blower

4. Exhaust vent

5. Control panel

1. Microwave power generator/processor: The processor is provided with three

magnetrons of 1 kW each producing @ 2450 MHz. These magnetrons are located

in a metal housing which forms a continuous tunnel. The three magnetrons are

located adjacent to each other inside the tunnel. The sector of the tunnel where

these magnetrons are located forms the microwave cavity where actually

heating/processing takes place. Each of the magnetrons is controlled by an

independent switch. One, two or all the three could be operated as desired. The

total length of the tunnel is 3.0 m of which 2.0 m forms the cavity where actual

microwave heating takes place. The product travels into the cavity inside the

tunnel over a conveyor.

2. Conveyor mechanism: The conveyor mechanism consists of two rollers driven

by variable speed DC drive mechanism. An endless belt made of “Teflon” cloth

is fitted over the rollers and forms a continuous moving conveyor inside the

tunnel. The speed of the conveyor could be varied from 0- 6m/min. The samples

for processing are kept on this conveyor belt and as it moves through the cavity,

processing takes place because of microwave impinging.

3. Blower: Two blowers are provided at either end of the chamber to pass air over

the product for cooling.

4. Exhaust vent: Exhaust vent removes the air out of the system.

5. Controls panel: Magnetron switches, conveyor speed control switches, blower

switches, and main control are all provided in the control panel.

Fig -2. Continuous Microwave Processor

Photo No-1. Continuous microwave processor

Photo No-2. Vacuum package

Photo No-3. Texture analyzer

Photo No-4. Paneer spread on bread

3.1.11.3 Mixer grinder

Maharaja white line mixer grinder was used for mixing/grinding the ingredients to

get smooth, soft and spreadable product.

3.1.11.4 pH meter.

Elico digital pH meter was used for determination of pH of paneer spread.

3.1.11.5 Water bath.

Thermostatically controlled water bath supplied by Sleek Company, Bangalore

was used

3.1.11.6 Incubator

Digital incubators supplied by Serwell Instruments, Bangalore was used in the

study.

3.1.11.7 Homogenizer

Lab model two-stage homogenizer ‘Rannie’ imported from Copenhagen was used

for homogenization of filled milk base for spread preparation.

3.1.11.8. Penetrometer

Cone penetrometer supplied by Associated Instrument Manufacturers (I) Pvt. Ltd.

(AIMIL) was used to measure the firmness of paneer spread samples.

3.2. METHODS.

3.2.1 Optimization of processing parameters

3.2.1.1 Preparation of paneer.

Paneer was prepared as per the method suggested by Bhattacharya et al. (1971) with

slight modifications. The standardized milk (4.5% fat and 8.5% MSNF) was heated to

90°C (No holding) in a stainless steel vessel followed by cooling to 70°C. Then hot

solution (70°C) of one percent citric acid was added to the milk (70°C) with vigorous

agitation initially and gentle stirring later till clear whey was separated out. Then the

coagulum was allowed to settle down for 5 minutes. The whey was drained out through a

muslin cloth and collected paneer curd was used for preparation of paneer-spread.

3.2.1.2. Preparation of paneer spread.

The method suggested by Reddy et al. (2000) for the preparation of chhana butter

spread was adopted for the preparation of paneer spread in the study with slight

modifications. The final procedure is shown in the flow chart-1. About 0.25 kg of freshly

prepared paneer curd was transferred to the mixer jar, various levels of common salt

(NaCl) and tri sodium citrate was added to the paneer curd at the rate of 0.5 per cent.

Then calculated amount of pasteurized potable water was added to adjust the moisture

content of the product to 63.5 per cent (to facilitate proper grinding/mixing process). The

jar contents were subjected grinding to obtain smooth spreadable product. Finally the

Standardized milk

(4.5% fat & 8.5%SNF)

Heating (90oC/No Hold)

Flow chart-1. Process optimization for manufacture of paneer spread

product was transferred to 100 ml polystyrene cups and stored at refrigeration

temperature for further studies.

Cooling (60,65,70 or 75oC)

Addition of citric acid solution (1, 2, 3 or 4%)

Complete coagulation of milk

Paneer curd

Addition of water to adjust moisture

Addition of salt (@ 1.5%) & stabilizer (@ 0.5%)

Grinding (1,2,4 or 6 min)

Filling (Polystyrene Cups)

Storage at 7oC

3.2.1.3 Optimization of coagulation temperature.

Standardized milk was heated to 90°C and cooled to various temperatures

separately (60,65,70 or 75°C) and added with citric acid solution with respective

temperature of 60,65,70 and 75°C for complete coagulation. Then the paneer spread was

prepared as per the procedure mentioned in the section 3.2.1 to find out the optimum

coagulation temperature (flow chart -1)

3.2.1.4 Optimization of concentration of the coagulant

Various concentration of the citric acid solution such as 1, 2, 3 and 4 per cent

levels were tried during optimization of the concentration of the coagulant

3.2.1.5 Optimization of the grinding duration

Paneer curd was grinded at different durations such as 1, 2, 4 and 6 minutes

during optimization of grinding time

3.2.1.6 Optimization of salt content

Various levels of salt such as 0.5, 1.0, 1.5 or 2.0 per cent was incorporated to

paneer curd during optimization of salt taste to the paneer curd

3.2.2 Incorporation of WPC or sodium caseinate in the development of paneer

spread.

3.2.2.1 Levels of WPC.

The WPC was incorporated into paneer curd at 2, 5, 10 or 15 per cent by weight

of paneer curd. Calculated amount of paneer curd and WPC were heat processed and

transferred to the mixing/grinder along with common salt and tri sodium citrate. Then the

product was prepared as per the procedure mentioned in the section 3.2.1 and flow

diagram-2.

3.2.2.2. Levels of sodium caseinate.

The sodium caseinate was incorporated in to paneer curd at 2, 5, 10 or 15 per cent

by weight of paneer curd. Calculated amount of paneer curd and Sodium caseinate were

transferred to the mixing/grinding jar along with salt and tri sodium citrate and then the

product was prepared as per the procedure mentioned in the section 3.2.1 and flow

diagram-2.

3.2.3 Incorporation of soy flour in paneer spread.

The paneer spread was prepared by incorporating soy flour at 2, 5, 10 or

15 per cent by weight of paneer curd and the product was prepared as per the procedure

of 3.2.1 and flow diagram-3

Fresh Paneer curd

Adding salt @1.5% and stabilizer @0.5%

Flow chart-2. Preparation of paneer spread incorporated with WPC/ Sodium caseinate

Heating 80°C/No Hold

Grinding

Filling (Polystyrene cups)

Storage at 7°C

Addition of WPC or Sodium caseinate (2,5,10 or 15% level)

Fresh Paneer curd

Flow chart-3. Preparation of paneer spread incorporated with soy flour

3.2.4 Preparation of filled paneer spreaed.

Addition of salt (1.5%) and stabilizer (0.5%)

Addition of soy flour at the rate of 2, 5, 10 or 15% level

Heating to 80°C /No hold

Grinding

Cup Filling (Polystyrene cups)

Storage at 7°C

Blending

The filled paneer spread was prepared by replacing milk fat with vegetable oil or soy

flour at the following levels.

3.2.4.1 Replacement of milk fat with vegetable oil

Milk fat was replaced with sunflower oils at 0, 25, 50 or 75 per cent levels to

prepare four different lots of base mix for manufacture filled paneer spread. The base mix

was subjected to two stage homogenization and the spread was manufactures as

mentioned in the section 3.2.1 and Flow chart-4. Similarly, corn oil and soy oil were also

used to replace milk fat as mentioned above to obtain filled paneer spread lots.

3.2.4 Incorporation of flavour enhancers in paneer spread.

Various flavour enhancers were used in paneer-spread preparation to study the

effect of on acceptability of the product.

3.2.4.1 Cheese.

Cheddar Cheese was mixed with paneer curd at 20, 30 or 40 per cent levels. Then the

product was prepared as per the procedure mentioned in the section 3.2.1.

3.2.4.2 Chakka

Chakka was mixed with paneer curd at 10, 20, 30 and 40 per cent levels. The

product was prepared as per the procedure outlined in the section 3.2.1.

Skim milk

Adding cream and vegetable oils (Replacement of milk fat with vegetable oil at 25,50,75% level)

Flow chart-4. Preparation of filled paneer spread. 3.2.4.2 Spices

Various spices were used at different levels as mentioned below:

Sunflower oil Corn oil Soy oil

Blending and pre heating to 65oC

Homogenization

Heating at 90oC/No holding, cooling to 65oC and coagulation

Whey separation

Paneer curd

Grinding

Storage at 7oC

Filling (Polystyrene Cups)

Addition of salt @ (1.5%) and

trisodium citrate @ (0.5%)

3.2.4.2.1 Spice powder

Pepper powder was used at 0.5, 1, 1.5 and 2 per cent levels by weight of paneer

curd. The paneer spread production was carried out as per the procedure given in the

section 3.2.1. The incorporation of spice powder was done at the time of grinding

processes. Similarly, other spices such as clove, cinnamon and their combinations like

pepper and clove, clove and cinnamon and cinnamon and pepper powder were tried

during the development of spiced paneer spread.(Flow chart-5)

3.2.4.2.2 Spice extract

Pepper powder at 0.5, 1, 1.5 and 2 per cent by weight of paneer curd was soaked

in little quantity of boiling water, then the filtered extract was incorporated at the time of

grinding processes of paneer spread production (Section 3.2.1.). Similarly, other spice

extracts such as clove, cinnamon and their combinations like pepper and clove, clove and

cinnamon, cinnamon and pepper were tried for the manufacture of spiced paneer spread

(flow chart-5)

Fresh Paneer curd

Flow chart-5. Preparation of spiced paneer spread 3.2.1 ANALYTICAL METHODS.

The analytical methods employed in the chemical analysis are follows.

Addition of salt (1.5%) and stabilizer (0.5%)

Addition of pepper powder or clove powder or cinnamon powder or mixtures of pepper and clove or clove and cinnamon or cinnamon and pepper powder and their extracts at 0.5, 1.0, 1.5 or 2.0 % level

Heating to 80°C /No hold

Grinding

Cup Filling (Polystyrene cups)

Storage at 7°C

Blending

3.2.1.1 Milk

3.2.1.1.1 Fat

Fat content of milk, skim milk and cream was determined by Gerber method as

IS: 1479 (part I) 1981.

3.2.1.1.2 Milk solids not fat (MSNF)

The MSNF content of milk and skim milk was estimated by as per IS: 1479 part II

(1981) procedure.

3.2.1.1.3 Acidity

The titratable acidity of milk was determined as per the method given in IS: 1479,

(part 1), 1981.

3.2.1.2 Paneer spread

3.2.1.2.1. pH

pH of paneer spread sample was determined by blending 10g of paneer spread

with 10 ml of glass distilled water and dipping the electrode directly into the slurry as per

the procedure followed by O’ Keeffee et al. (1976).

3.2.1.2.2. Moisture

Moisture content of paneer spread was estimated as per IS: SP18 (Part XI) 1981

procedure.

3.2.1.2.3 Acidity

The titratable acidity of paneer spread was determined as per the procedure of

AOAC (33.7.14; 920.124, 1995).

3.2.1.2.4. Protein

The protein content of paneer spread was determined as per the procedure

mentioned in IS; SP18 (Part XI), 1981.

3.2.1.2.5 Soluble nitrogen

The soluble nitrogen content was determined as per Association of Official

Analytical Chemists (AOAC. 33.2.12; 991.21, 1995) procedure

3.2.1.2.6. Fat

Fat content of paneer spread was determined by Mojonnier fat extraction method

as per the procedure of IS: SP18 (Part XI) 1981.

3.2.1.2.7 Free fatty acid (FFA)

The free fatty acid (FFA) content of paneer spread was estimated using the

procedure mentioned by Deeth et al. (1975). One gram of sample was transferred into a

35 ml screw cap test tube, mixed with 10 ml of extraction mixture (Iso-propanol:

petroleum ether: 4N H2SO4 :: 40: 10 :1) , further 6 ml of petroleum ether and 4 ml of

distilled water were also added. The test tube was shaken vigorously for 15 s and two

layers are allowed to settle. An aliquot of the upper layer is withdrawn and transferred in

to a 50 ml conical flask. Six drops of 1 per cent methanolic phenolphthalein was added

and the solution was titrated against 0.02N methonolic KOH. A blank reading was

carried out using distilled water in place of paneer spread. The FFA content of paneer

spread was obtained using the following formula:

Free Fatty Acids ( equl./g) = TxNx103

PxG

Where:

T= Net titration volume

N=Normality of methanolic KOH

P=Proportion of upper layer titrated (i.e. volume of aliquot withdrawn/ total

volume of upper layer)

G=Weight of the sample

3.2.2 Microbiological quality

The paneer spread samples were analyzed for total count (TC), coliform count,

yeast and mould count using various agar medium (Hi-media Laboratories Pvt. Ltd.

Bombay)

3.2.2.1 Total count

The total count was estimated on plate count agar (PCA) medium as per the

procedure given in (IS : 1224 part I and Part II, 1981)

3.2.2.2 Coliform count

Coliform count was carried out on dehydrated violet red bile agar (VRBA)

medium (IS : 1224 : part I and Part II, 1981)

3.2.2.3 Yeast and mould count

Yeast and mould count was determined using malt extract agar (MEA) medium

using the procedure given in (IS : 1224 part I and II, 1981). The MEA pH was adjusted to

3.5 by adding sterilized lactic acid (10 %) solution aseptically to the molten medium

immediately before pouring into the plates

3.2.3 Rheology of paneer spread

Spreadability, Firmness, Adhesiveness and Stickiness were determined by using

Texture Analyzer ( Model - TA-XT2) at National Dairy Research Institute (NDRI),

Audugodi, Bangalore.

Texture analyzer with the following specifications was used to determine the

rheological characteristics of paneer-spread samples:

Make Stable micro-system

Model TA-XT2

No. of compression Two stage

Load cell 25 kg

Power 230 V AC (2.2 KVA)

Standard settings of Texture Analyzer (TA) are as follows:

Caption Value/unit

Test mode Compression

Pre-test speed 1 mm/s

Test speed 2 mm/s

Post test speed 10 mm/s

Target mode Distance

Distance 5 mm

Trigger type Auto (force)

Trigger force 5 g

Break mode Off

Stop plot at Start position

Tare mode Auto

Advanced caption On

Control oven Disabled

3.2.3.1 Texture profile analysis

Texture profile analysis (TPA) parameters were determined by using the Stable

Micro-Systems TA-XT2 Texture Analyser (UK) fitted with 25 kg load cell was used for

two-stage liner compression of paneer spread samples. A cone type probe was attached to

the moving cross-head. Various textural parameters determined include firmness,

stickness, spreadability and adhesiveness . The hardness/ firmness is the maximum peak

force (F) during the first compression cycle (first bite) and the unit is Newton. The

stickiness is the negative peak force (F) during the second compression cycle (second

bite) and the unit is Newton. The spreadability is the area of positive curve (Area 1:2)

and the adhesiveness is the area of negative curve (Area 3:4). The unit of spreadability

and adhesiveness is Newton/s (Appendix-III).

3.2.4 Penetration measurement

The penetration measurements were made using cone and test rod (probe)

weighing 35g . The cone was allowed to penetrate the sample for a fixed time of 5 s. For

the same sample, reading was recorded at different spots and the average value was

recorded as mm/5 s of penetration.

3.2.5 Sensory evaluation.

A panel of 5 Judges evaluated the organoleptic quality of paneer spread. Each

judge was provided with a score card (Appendix 1 or 2) and bread slice along with

paneer spread to assess the quality of product with respect to various attributes such as

colour and appearance, body and texture, flavour, spreadability and overall acceptability.