Claims:CLAIMS

We claim:
1. A food pack consisting of ready-to-cook fermented batter having stability at ambient temperature, comprising of:
i. fermented batter consisting of rice, black gram in weight ratio from 3:1 to 5:1) and having a viscosity of 10000 to 35000 cp and a pH between 5.8 to 6.3 and lactic acid bacteria in a range from 106 to 108 cfu/g,
ii. outer packing having controlled transmission laminate with carbon dioxide transmission rate in the range from 4000 to 5000 cc/m2/24 hr/ 73degF, 1atm and an oxygen transmission rate in the range from 1000-2000 cc/m2/24 hr/ 73degF, 1atm;
Characterized in the food pack is withstand the microbial count of said fermented batter within the range from 106 to 109 cfu/g when stored at ambient temperature selected from 20 to 40 °C for upto 4 days.

2. The food pack as claimed in claim 1, wherein fermented batter is selected from batter for idli, dosa, uttapam, vada and dhokala.

3. A process of production of ambient temperature stable ready-to-cook fermented batter food pack comprising steps of:
a) preparing of fermented batter consisting of rice, black gram and salt having a viscosity of 10000 to 35000 cp and a pH between 5.8 to 6.3 and lactic acid bacteria in a range from 1010 to 1012 cfu/g,
b) packing step a) batter in a pouch of flexible structure styrene based materials of packaging,
c) sealing a pack,
d) heat treatment by placing the pack in water bath,
e) Intermediately shaking the pack,
f) Gradually cooling at ambient temperature.
Characterized in the integration of heat treatment and gas-permeable laminate retard the microbial growth of batter and prevent gelatinization during thermal effect.

4. The process as claimed in claim 3, wherein preparation of fermentation of batter is selected from natural fermentation process for time selected from 6 hr to 24 hr and using fermentation starter.

5. The process as claimed in claim 3, wherein the flexible structure packing pouch is having a controlled transmission laminate with carbon dioxide transmission rate in the range from 4000 to 5000 cc/m2/24 hr/ 73degF, 1atm and an oxygen transmission rate in the range from 1000-2000 cc/m2/24 hr/ 73degF, 1atm.

6. The process as claimed in claim 3, wherein the heat treatment is selected from temperature 35 to 80 °C for time ranging from 30 to 120 minutes.

7. The process as claimed in claim 3, wherein intermediate shaking is at interval of 15 to 30 minute.

8. The process as claimed in claim 3, wherein shaking speed is selected from 10 to 20 rpm.

Dated this 26th day of September 2018.
, Description:FIELD OF INVENTION
The present invention relates to a ready-to-cook fermented batter packed in breathable packing material having shelf life at ambient temperature. More specifically, the present invention relates to a process for production of fermentation controlled food product providing an ambient temperature stable to a fermented batter pack food, preferably shelf stability at 20 to 40 ºC.

BACKGROUND AND PRIORART OF THE INVENTION
Idli, dosa and vada are a traditional rice-black gram based breakfast foods, prepared after fermenting substrates by a variety of microorganisms to yield products with unique and appealing characteristics. The fermentation takes place due to the microflora present in the raw materials and in the environment leading to the several changes that has impact on digestibility and nutritional value in food.
During the fermentation of rice-black gram batter different physico-chemical changes occur. Total acidity of the batter increases during the fermentation of the batter. The essential physical change in the batter is that it becomes leavened by CO2 gas as well as a pleasant flavour develops. The standard idli batter preparation process consists of three major steps – soaking of rice and dehulled black gram (4 – 6 hours), wet grounding and fermentation (12 – 18 hours at 30 °C) Consequently, the whole procedure in home scale takes about 20 hours and the idli preparation process is laborious. Additionally, household prepared idli batter lacks in consistent quality. These problems have made consumers to prefer the ready-to-cook idli batter from domestic markets.
If freshly prepared batter is kept for more than 2 days, the batter mixture starts over fermenting and finally decomposing. To stop further fermentation and increase the shelf life, batter need to store at very low temperature, preferably below 10 °C, more preferably below 0 °C. Accordingly, the commercially available ready-to-cook idli batter need cool temperature storage conditions.
The amount of microflora (10-10- 10-11 cfu/g) like lactic acid bacteria (LAB) and yeast in fermented idli batter is very important with respect to idli texture, quality and safety including maintaining its characteristic spongy structure, desirable sour taste and good aroma. The same applies for other food products like dosa, uttapam, vada, dhokala etc.The presence of high amounts (10-10- 10-11 cfu/g) of lactic acid bacteria and yeast, and their activity during storage could be one of the main reason for spoilages of idli batter quality.
Some have suggested that modified atmospheric packaging may be used to pack the freshly prepared batter. These are packaged in either Low Density Poly Ethylene (LDPE), Poly propylene (PP), Polyethylene terephthalate (PET), Polyvinylidene chloride (PVDC) or High Molecular (HM) bags.
The article of M. DURGADEVI (MODIFIED ATMOSPHERE PACKAGING OF READY TO COOK IDLI BATTER) describes ready to cook idli batter packaged in medium thickness (0.012 mm) LDPE flushed with 0% CO2 and 7.5 to 15% O2 could increase the shelf-life without compromising the sensory qualities at room temperature. It has certain limitations, specifically in accordance with respiration dynamics, an important phenomenon in the fermentation process. In respiration dynamics, the percentage of oxygen utilized and percentage of carbon dioxide released during fermentation of batter is determined. Hence, the above said packaging failed to hold the level of carbon dioxide released as time passes. Such continuous fermentation and releasing of carbon dioxide resulted in the marked swelling of the packaging and also increased the inside pressure, which may cause the contents to leak.
Indian Patent application no. 354/CHE/2014 discloses the method to extend the shelf life of idli batter, wherein the batter is subject to pre-freezing at -200C for 1 hr and then shifting at 40C. The said method utilizes a deep freezing technique which is a costly technology.

Generally, during fermentation of idli batter overnight the naturally occurring microorganisms viz. Leuconostoc mesenteroides and Streptoccous thermophilus in grains/legumes/utensils grow rapidly, outnumbering the initial contaminants and dominating the fermentation. These microorganisms produce lactic acid (=1.0%) and carbon dioxide that make the batter anaerobic and leaven the product. In view of respiration dynamics of fermented food, it is desired to have packaging that is selectively permeable to carbon dioxide/oxygen gas.
WO 2016021842 A, discloses a fermented food packaging pouch and packaging method using the same, particularly, packaged kimchi. The patent application discloses a gas absorbent food packaging pouch that prevents swelling within the pouch by absorbing carbon dioxide gas. This packaging system prevents bulging of bag but fails to prevent over fermentation resulting into undergoing chemical changes that give rise to unpleasant aromas.
A publication with entitled “PROCESSING AND MICROBIOLOGY OF IDLI, INDIAN CEREAL-LEGUME FERMENTED FOOD” by Suresh Chander Chandrasekar Rajendran, Helsinki, 2014; discloses pre-pasteurization or mild heat treatment that inactivates a significant amount of vegetative microorganisms in batter, wherein batter samples in tubes were capped and treated at 57, 60, 63, 66 and 70 °C in a water bath for 10 min and stored for 10th day of storage at 4 °C. These cooked idli do not possess the characteristic texture and also lack the typical fermented aroma. Because gelatinization of starch present in batter due to heat treatment.
Indian Patent application no. 201721001565, discloses fermentation controlling packaging system for ready-to-cook batter having a specific gravity of 0.5 to 1.5 kg/m3and a pH of 4.5 to 6.5 packed in a gas-permeable laminate having flexible structure materials for packaging. But, batch to batch controlling physical characteristic of batter i.e. acidity and specific gravity before packing limit the stability performance of packed food and hence large-scale production.
As per above listed prior arts, instant idli pre-mixes/batter are available, these do not possess the characteristic texture and also lack the typical fermented aroma. Although cooked idli or dosa from available ready-to-cook batter do not have consistent quality as room temperature favorably support the growth of lactic acid bacteria dominated in batter when removed from refrigeration condition and seen bulging of packets or affect the organoleptic properties after steaming/cooking.
Thus, because of unavoidable effect of room temperature (varies from 20 to 40 ºC), uncontrollable acidity level, unstable batter consistency, limitation of refrigeration storage condition affecting the large-scale production and stability of such in-situ fermented batter. A need thus exists for improved methods of supplying and preparing ready-to-cook fermented batter such as idli batter, vada batter and dosa batter having shelf stable at room temperature (20 to 40 ºC).
Surprisingly, inventors of the present invention have developed a method for effective retarding anaerobic bacterial growth using thermal technique without gelatinization followed by packing into specially developed controlled respiration of gases to maintain the microbial flora in fermented batter and thus good taste and texture consistency of cooked food. The present invention provides an effect process for large scale production of fermentation controlled ready-to-cook, shelf stable food products.

SUMMARY OF THE INVENTION
The present invention relates to a ready-to-cook fermented batter pack product having stability at ambient (room temperature ranging from 20 to 40ºC) and process of production thereof.
Accordingly, the present invention provides a process for production of fermentation controlled food product providing an ambient temperature stable to a fermented batter pack food, preferably shelf stability at 20 to 40 ºC.

In one aspect, the present invention provides a food pack consisting of ready-to-cook fermented batter with stability at ambient temperature, comprising of:
i. fermented batter consisting of rice, black gram in weight ratio from 3:1 to 5:1) and having a viscosity of 10000 to 35000 cp and a pH of 5.8 to 6.3 and lactic acid bacteria in a range from 106 to 108 cfu/g,
ii. outer pack having controlled transmission laminate with carbon dioxide transmission rate in the range from 4000 to 5000 cc/m2/24 hr/ 73degF, 1atm and an oxygen transmission rate in the range from 1000-2000 cc/m2/24 hr/ 73degF, 1atm;
Characterized in the food pack is withstand the microbial count of said fermented batter within the range from 106 to 109 cfu/g when stored at ambient temperature selected from 20 to 40 °C for upto 4 days.

In another aspect, the present invention provides a process of production of ambient temperature stable ready-to-cook fermented batter food pack comprising steps of:
a) preparing of fermented batter consisting of rice, black gram and salt having a viscosity of 10000 to 35000 cp and a pH of 5.8 to 6.3 and lactic acid bacteria in a range from 1010 to 1012 cfu/g,
b) packing step a) batter in a pouch of flexible structure styrene based materials for packaging,
c) sealing a pack,
d) heat treatment by placing the pack in water bath,
e) Intermediately shaking the pack,
f) Gradually cooling at ambient temperature.
Characterized in the integration of heat treatment and gas-permeable laminate retard the microbial growth of batter and prevent gelatinization during thermal effect.

The invention is pertain to large scale production of ready-to-cook fermenting food product having stability at ambient temperature and a process for production of fermentation controlled food product, thereby providing a cost saving in cold storage requirement of related fermented products and hence, the present invention is more economic as compare to available ready-to-cook fermented food products such as idli batter, vada batter etc.

DETAILED DESCRIPTION OF THE INVENTION
In some embodiments, the ready-to-cook fermented batter may also be referred to as “fermented batter”, “idli batter”, “batter”, “ready-to-cook idli batter”, “food batter”, “fermented idli batter”, “ready-to-cook batter”, “idli batter”, “vada batter”, “dhokla batter”.
The term "fermented" refers to the final batter produced after fermentation by natural process or by using starter such as inoculated lactobacillus culture, or any other bacteria well known to those skilled in the art that causes fermentation.
Embodiments of methods and packaging for preparing fermented batter are described hereinafter. Although the embodiments are particularly described with reference to rice-black gram based in-situ fermenting batter, it is not intended that the present invention be restricted in this way. Specifically, the present invention has application to other types of batter and particularly to other compositions for human consumption, such as dhokala, amboli, khaman, and uttapam.
In order to obviate the aforementioned drawbacks in the existing prior art, the present invention relates to a process for production ambient temperature stable food pack of ready-to-cook/steam fermented batter prepared using and not limiting to rice, black gram and salt.
The present invention provides an effect process for large scale production of fermentation controlled ready-to-cook, shelf stable food products. The said process and methodology effectively retarding anaerobic bacterial growth using thermal technique without gelatinization followed by packing into specially developed controlled respiration of gases to maintain the microbial flora in fermented batter and thus good taste and texture consistency of cooked food.
More preferably, the present invention relates to a ready-to-cook, ready-to-steam fermented batter food product comprising of fermented batter comprising of blend of watery slurry, air, acid, micro-organism dominantly lactic acid bacteria and yeast, packed in breathable bag, wherein the said fermented batter is stable at ambient temperature and having control on growth of microbial counts in batter during stability period.
In accordance to main embodiment, the present invention provides an integrated method of retarding anaerobic microbial growth in batter and protective packing having properties of minimization of anaerobiosis originating from the accumulation of CO2 in packaging. The fermented batter generally comprises of dominantly a lactic acid bacteria (LAB) count ~1010 cfu/g and they grow well at low pH and at ambient temperature i.e. above 15 to 20 °C. Additionally, the yeasts are capable of producing amylases which were absent in the LAB strains. Accordingly hypothesized the functions of the LAB were to reduce the pH of the batter by increasing the acidity level and thereby favoring the activity of the yeast. In turn, yeast complements the growth of LAB by breaking starch through extracellular amylolytic enzymes. However, the synergism between LAB and yeasts is yet to be ascertained.
Hence, the present invention provides an integrated and effective solution for large-scale production of ready-to-cook fermented batter consisting food pack meant for steaming or cooking with minimal control on physical properties of said batter during production and enabling automation of the filling lines. The invention also provides means for storage and customer acceptancy of these batter effectively with minimal caution about storage condition and without the chance of any unavoidable over fermentation, bloating and leakage of packed batter.
According to one of the embodiment the present invention provides a food pack consisting of ready-to-cook fermented batter with stability at ambient temperature, comprising of: fermented batter consisting of rice, black gram in weight ratio from 3:1 to 5:1) and having a viscosity of 10000 to 35000 cp and a pH of 5.8 to 6.3 and lactic acid bacteria in a range from 106 to 108 cfu/g and outer packing having controlled transmission laminate with carbon dioxide transmission rate in the range from 4000 to 5000 cc/m2/24 hr/ 73degF, 1atm and an oxygen transmission rate in the range from 1000-2000 cc/m2/24 hr/ 73degF, 1atm;
Characterized in the food pack is withstand the microbial count of said fermented batter within the range from 106 to 109 cfu/g when stored at ambient temperature selected from 20 to 40 °C for upto 4 days.

The pasteurization of batter can be used to retard the fermenting bacteria once the desired fermentation is occurred and breathable packing material used to maintain the acidity during storage period. This, integration of a pasteurization and specific breathable packing can be accomplished in a large-scale production of ready-to-cook food product having stability at ambient temperature i.e. 20 to 40 °C.
According to second embodiment, the present invention provides a process of production of ambient temperature stable ready-to-cook fermented batter food pack comprising steps of:
a) preparing of fermented batter consisting of rice, black gram and salt having a viscosity of 10000 to 35000 cp and a pH of 5.8 to 6.3 and lactic acid bacteria in a range from 1010 to 1012 cfu/g,
b) packing step a) batter in a pouch of flexible structure styrene based materials for packaging,
c) sealing a pack,
d) heat treatment by placing the pack in water bath,
e) Intermediately shaking the pack,
f) Gradually cooling at ambient temperature.
Characterized in the integration of heat treatment and gas-permeable laminate retard the microbial growth of batter and prevent gelatinization during thermal effect.

For making fermented batter, the traditional process is followed where batter is prepared by soaking rice and decorticated black gram, optionally addition of fenugreek seeds for 4 h at 30?±?1 °C in water. The soaked mass was ground using a grinder with adequate amount of water. The blend ratios selected from 2:1, 3:1 and 4:1 (w/w) batter are allowed for fermentation for over night with the addition of 2% (w/w) of salt.
Idli batter being a live/ dynamic product keeps changing its flora, consistency and chemical parameters everyday based on weather, time of processing and duration as well. The process as per present invention helping to arrest/ retard the natural fermentation microflora, which otherwise increases in the batter and results in acidified and over fermented batter. Pasteurization or mild heat treatment is a process that inactivates a significant amount of vegetative microorganisms in food. The main objective of this process is to reduce the microbial growth in food for better safety handling and storage. It is one of the minimal processing methods available that does not affect the nutritional and sensory characters of the food. In the literatures available, heat treatment of foods with in the temperature range 55 – 80 ?C has been referred as pasteurization or mild heat treatment process. However, all LAB and yeast species could not be inactivated by mild heat treatment or starch gelatinized if used accelerated heat temperature or pre-pasteurization technique.
Accordingly, the present invention relates a method of retarding the anaerobic microbial growth of fermented batter during storage at room temperature, preferably from temperature 20 to 40 ºC, method comprising of step; packing said fermented batter in a breathable package having specific gas transmission rate, subjecting pack to thermal treatment, wherein said package is shaken intermediately during thermal treatment, cooling to room temperature.
Accordingly, the present invention the ready-to-cook fermented batter which undergo post packing pasteurization process to retard the microbial growth of Lactic acid bacteria, maintain the food value thereof and retain the starch content available for effective consistency after cooking.
The present invention is further described with the help of the following examples, which are given by way of illustration all the parts, percent and ratios are by weight unless otherwise indicated and therefore should not be construed to limit the scope of the invention in any manner.
EXAMPLES:
Example 1: Preparation of Idli Batter:
Conventional method: Rice and black gram (urad dal) weighed in ratio of 4:1 and soaked for 3 to 12 hr. They were ground separately and then mixed. All grinding was done with water as a medium. Allowed to ferment for time between 3 to 6 hr before being packaged.. A fermented batter with effective viscosity in the range from 15000 to 22000 cp and pH 5.8 to 6.3 were successfully prepared.

Example 2: Method of production ready-to-cook food pack as per present invention:
Freshly prepared fermented batter was packed in pouches and sealed. The pouch structures of this invention can be prepared from sheets of material having different gas transmission rate for Oxygen and Carbon dioxide, which are folded upon themselves in many numbers/layers of configurations. Seams are typically glued or welded together using methods such as ultrasonic energy, heat or thermosetting material.
Subjecting packed and unpacked batter for mild heat treatments at different temperature to analyze its effects on LAB and yeast population. For the thermal treatments, the bags were filled and sealed and treated at 60 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C & 95 °C in a water bath from 5 min to 2 hours. During heat treatment, the pouch was shaken for definite time interval (15 min, 20 min and 30 min) to achieve uniform heating in the pack. After each treatment, the temperature inside the sample was measured and then cooled for 10 min. Further, the Microbial load and sensory score were analyzed for freshly packed batter and for batter kept in stability (at chilled and temperature 20 to 40 °C) chamber using packing material listed in table 1.

Table 1: Type of packing pouches:
Sr. No. Type of Pouch OTR
[cc/m2/24 hr/ 73degF, 1atm] COTR
[cc/m2/24 hr/ 73degF, 1atm]
1. Barrier Type
(nylon or EVOH based) 10-15 30 -50
2. Breathable Type
(PE based) 7000-9000 23000- 26000
3. LDPE type (PE+LDPE based) 400-600 1500
4. Controlled transmission Type (styrene based)-Transparent 1000-2000 4000-5000
5. Controlled transmission Type (styrene based)- Opaque 1000-2000 4000-5000

Stability experiments were repeated a couple of times in chilled and ambient storage with freshly fermented idli batter and the unheated, unpacked fermented idli batter was considered as control. Microbiological analysis Influence of the mild-heat treatments on LAB and yeasts Colony Forming Units (CFU) were determined by Total-Plate Count method (TPC), using spread plate technique. The replicates of thermally treated and untreated samples (0.1 g) were taken in Eppendorf tubes and homogenized with 0.9 ml sodium chloride solution (0.85%) for 2 min in the shaker at an optimal speed. Thereafter, the samples were serially diluted to tenfold and using a sterile bent glass rod, desired dilution (0.1 ml) was spread plated on de Man, Ragosa, Sharpe (MRS; Oxoid Ltd., UK) and yeast peptone dextrose (YPD, Appendix 1) agar plates for LAB and yeast count, respectively. The plates were incubated aerobically for 24 to 48 hours at 30 °C and the CFU of LAB and yeast were enumerated
The testing parameters includes initial viscosity and acidity, microbiological counts, smell and physical parameters, and finally heat and sensory test. The results are depicted in table no. 2.
Wherein Sensory Score scale refers to following food’s taste acceptancy:

Table 2: Score of Sensory Scale
Sensory Score Acceptability
1 Dislike extremely
2 Dislike moderately
3 Neither like nor dislike
4 Like moderately
5 Like extremely

The process of packing does not involve Pasteurization and packing material is selected from breathable Type PE pouch.

Table 32: Effect of Batter Consistency on shelf life stored at room temperature:
Initial pH Viscosity (cp) Shelf Life in Ambient (Days) Remarks
4.0 10,500 1 Day 2 onwards bloating was seen and Idli was sour in taste
4.2 10,500 1 Day 2 onwards bloating was seen and Idli was sour in taste
4.4 25,000 1 Day 2 onwards bloating was seen and Idli was sour in taste
4.7 25,000 1 Day 2 onwards bloating was seen and Idli was sour in taste
5.0 25,000 1 Day 2 onwards bloating was seen and Idli was sour in taste
5.5 28,000 2 Day 3 onwards bloating was seen and Idli was sour in taste
5.7 28,000 2 Day 3 onwards bloating was seen and Idli was sour in taste

A. When Packed in breathable Type PE pouch : The process of packing does not involve Pasteurization and packing material is selected from breathable Type PE pouch.
Table 43: Effect of temperature on shelf life of batter packed in breathable pouch and when stored at chilled temperature (2 to 4 ºC):
Day of Shelf Life Viscosity
(cp) Acidity
(Anhydrous Lactic Acid mg/kg) Sensory Score
Freshly prepared (Initial) 10000 5.4 5.0
Day 1 5533 7.30 5.0
Day 2 8400 7.92 5.0
Day 3 8800 7.92 4.5
Day 4 8600 7.38 4.0
Day 5 12600 8.46 3.5
Day 6 9466 8.92 3.0
Day 7 4133 9.10 1.0

B. When Packed in Controlled transmission Type pouch as per present invention: The process of packing does not involve Pasteurization and packing material is selected from Controlled transmission Type (Transparent and Opaque) pouch.

Table 54: Effect of temperature on shelf life of batter packed in controlled transmission type pouch and when stored at chilled temperature (2 to 4 ºC):

Day of Shelf Life Packaging Material Viscosity
(cp) Acidity
(Anhydrous Lactic Acid mg/kg) Sensory Score
Initial - 25200 5.4 5.0
Day 1 Transparent 20733 7.12 5.0
Opaque/White 22600 6.84 5.0
Day 2 Transparent 17666 7.23 5.0
Opaque/White 20666 7.66 4.5
Day 3 Transparent 15000 7.63 4.5
Opaque/White 19466 7.41 5.0
Day 4 Transparent 17200 8.28 4.0
Opaque/White 16933 8.46 4.0
Day 5 Transparent 7533 8.42 4.0
Opaque/White 10400 8.74 4.0
Day 6 Transparent 8466 7.66 4.0
Opaque/White 13000 7.77 4.0
Day 7 Transparent 14000 7.99 2.0
Opaque/White 14533 8.06 2.0

Table 65: Effect of temperature on shelf life of batter packed in controlled transmission type pouch and when stored at ambient temperature (25 ºC):
Day of Shelf Life Packaging Material Viscosity
(cp) Acidity
(Anhydrous Lactic Acid mg/kg) Sensory Score
Initial Transparent 18066 7.70 5
Opaque/White 16933 7.41 5
Day 1 Transparent 9200 10.0 2
Opaque/White 9933 9.21 2

Example 3: Effect of Thermal treatment on Stability of Fermented batter:
The process of production fermented batter food pack comprising of following steps: Firstly, the fermented batter consisting of rice, black gram and salt having a specific gravity of 0.5 to 1.5 kg/m3 and a pH of 4.5 to 6.5 and lactic acid bacteria in a range from 1010 to 1012 cfu/g,
a) packing batter in a different pouches,
b) sealing a pack,
c) heat treatment by placing the pack in water bath,
d) Intermediately shaking the pack,
e) Gradually cooling at ambient temperature.

Table 7: Effect of pasteurization temperature on 50 °C for 30 min on stability of batter packed in different pouches and stored at ambient temperature: (Bloating observed)
Day of Shelf Life Packaging Material Viscosity (cp) Acidity (Anhydrous Lactic Acid mg/kg) Microbiological Analysis Sensory Score
TPC (CFU/mL) LAB (CFU/mL) Yeast (CFU/mL)
Initial Pasteurized (P) - - 1.09 × 107 1.87 × 105 3.5 × 106 -
Non- Pasteurized 13133 6.37 1.75 × 108 1.47 × 108 1.51 × 108 5
Day 1 White controlled transmission (P) 12533 10.33 1.86 × 107 9.5 × 106 2.50 × 106 2
Transparent controlled transmission (P) 10066 11.16 2.16 × 107 1.87 × 107 1.24 × 107 2
Control (P) 12066 11.34 1.52 × 107 1.26 × 107 1.82 × 107 2
Barrier (P) 10333 10.98 >3.0 × 107 >3.0 × 107 8.5 × 107 2

Table 8: Optimization of Pasteurization step after packing in Controlled Transmission type pouch as per present invention.
Day of Shelf Life Pasteurization Condition
Viscosity
(cp) Acidity
(Anhydrous Lactic Acid mg/kg) Sensory Score
Initial 70°C / 10 min 26333 4.14 5
75°C / 10 min 30666 9.36 2
80°C / 10 min 80266 7.92 2
85°C / 10 min Coagulation observed 7.88 0
90°C / 5min Coagulation observed 9.21 0

Table 9: Effect of pasteurization temp and packing in Controlled Transmission type pouch as per present invention and stored at ambient temperature (25 ºC).
Day of Shelf Life Packaging Material Pasteurization Condition Viscosity
(cp) Acidity
(Anhydrous Lactic Acid mg/kg) Sensory Score
Day 1 Opaque 70°C / 30 min 19933 8.1 5
Opaque 70°C / 60 min 21466 7.4 5
Opaque 70°C / 75 min 31400 6.80 5
Transparent 70°C / 30min 39866 6.62 5
Day 2 Opaque 70°C / 30 min 19466 9.86 4
Opaque 70°C / 60 min 33800 6.26 5
Opaque 70°C / 75 min 57666 4.46 5
Transparent 70°C / 30min 14133 12.74 2

Table 10: Optimization of pasteurization temp and packing in Controlled Transmission type pouch as per present invention and stored at ambient temperature:

Example 4: Optimization of process of pasteurization:
The process of production fermented batter food pack comprising of following steps: Firstly, the fermented batter consisting of rice, black gram and salt having a specific gravity of 0.5 to 1.5 kg/m3 and a pH of 4.5 to 6.5 and lactic acid bacteria in a range from 1010 to 1012 cfu/g,
a) Packing a batter in a pouch having controlled transmission rate (styrene based) with OTR in the range from 1000 to 2000 [cc/m2/24 hr/ 73degF, 1atm] and COTR 4000 to 5000 [cc/m2/24 hr/ 73degF, 1atm]
b) sealing a pack,
c) heat treatment by placing the pack in water bath,
d) Intermediately shaking the pack (preferably 30 minute interval) at rate of 10 to 20 rpm,
e) Gradually cooling at ambient temperature.

A. Effect of heat Before & After Packaging (pre and post-pasterization): The data was recorded for sample wherein heat treatment is given before the pouching (pre-pasterization) & after the pouching (Post-pasterization).

Table 116: Data of Pasteurization Stage in Controlled Transmission type pouch as per present invention and stored at ambient temperature (25 ºC).

Temp (°C) Time (Min) Pre-pasteurization Post pasteurization Remarks
71.2 60 Coagulates No coagulation Idli texture & taste is good; Day 2 onwards bloating is seen
71.2 70 Coagulates No coagulation Idli texture & taste is good; Day 2 onwards bloating is seen
71.2 75 Coagulates No coagulation Idli texture & taste is good; Day 2 onwards bloating is seen
71.2 80 Coagulates No coagulation Idli texture & taste is good; No Bloating seen for 3 days
71.2 90 Coagulates No coagulation Idli texture & taste is good; No bloating is seen even after 4 days
71.2 120 Coagulates No coagulation Idli texture & taste is good; No bloating is seen after day 5 in ambient

Observation: Fermented batter when subjected to heat treatment for more than 15 mins at 70°C & above unpouched, will coagulate due to starch gelatinization which results in clumping. This is unsuitable for idli processing.
Batter when subjected to heat treatment inside the pouch above 70°C can go on for up to 3 hrs. without coagulation. However, above 75°C, we have seen it will coagulate over long periods of time.
When Idli batter packed in pouches is subjected to post pasteurization at 70°C, the temperature inside the pack increases gradually with time. At the end of 120 mins of pasteurization, the maximum temperature reached is 68.5°C inside the pack.

Table 127: Gradient observed for Temperature changes inside the pack at Pasteurization step:

Time (min) Temperature
0 0°C
30 35°C
60 50°C
90 65°C
120 68.5°C

B. Stability Testing:
Table 138: Shelf Life of batter in different bags after post pasteurization:
Pouch type Shelf Life in Ambient (Hours/Days) Remarks
Barrier Type 2 Hours Bloating was observed within 2 hours of packing
Breathable Type 1 Day Spoilage was seen in 1 day
Controlled Transmission Type 4 Days No bloating was observed. Idli was good in taste and texture up to 4 days.

Table 149: Pouch Comparison after Post-pasteurization (after packing) of Idli Batter
Type of Pouch OTR COTR Remarks
Barrier Type 10-15 30 -50 Pouch bloating observed within 2 hours after PP
Breathable Type 7000-9000 23000- 26000 No pouch bloating observed; Batter spoilage with visible growth & viscosity decreased
LDPE Type 400-600 1500 Bloating & Spoilage was observed
Controlled Transmission Type 1000-2000 4000-5000 No bloating of pouch or spoiling of batter was observed

Table 1510: Stability data of ready-to-cook Idli batter food pack as per present invention stored at 25 °C:
Day of Shelf Life pH Acidity (Anhydrous Lactic acid – mg/kg) Remarks
1 6.5 5.7 No bloating was observed, Idli was good in taste and texture
2 6.0 6.0 No bloating was observed, Idli was good in taste and texture
3 5.8 6.4 No bloating was observed, Idli was good in taste and texture
4 5.8 6.8 No bloating was observed, Idli was good in taste and texture

Table 1611: Stability data of ready-to-cook Idli batter food pack as per present invention stored at Chilled Temperature i.e. 4 °C:

Day of Shelf life Pasteurization Condition (Controlled Transmission type pouch) Viscosity (cp) Acidity (Anhydrous Lactic Acid mg/kg) Sensory Score

2 70°C/120 min 20400 4.14 5
4 30800 4.32 5
8 41266 4.75 5
11 47600 4.75 5
17 47800 4.92 4.5

Table: 17: Stability at different Temperature for ready-to-cook Idli batter food pack as per present invention:
Sr. No. Temperature (°C) Shelf Life (Days) Remarks
1. 20 4 No bloating was observed, Idli was good in taste and texture up to 4 days
2. 30 4 No bloating was observed, Idli was good in taste and texture up to 4 days
3. 40 3 No bloating was observed, Idli was good in taste and texture up to 3 days

The invention likewise provides a process for production of fermentation controlled food product, since batter undergoes heterogeneous fermentation of LAB and Yeasts, they are present in the range of 109 -1011 in freshly prepared fermented batter and when steamed into food Idli, the food is white in color, soft and porous in appearance with a mild sour taste. But, when product is available in commercial market as a ready-to-cook food product, the said organisms keeps on growing at ambient temperature and exist need of cold storage chain supply, which making the production costliest. Wherein the packaging materials are preferably used for food and drink.

According to present invention, it provides a ready-to-cook fermenting food product having stability at ambient temperature and a process for production of fermentation controlled food product, wherein the post pasteurization works by arresting the growth of microbes before dispatch and specifically controlled transmission designed with controlled air permission rate to CO2 and Oxygen release for idli batter packaging is preventing bloating. Wherein the temperature and time of pasteurization is vital, else it will coagulate starch in batter and Post pasteurization improves viscosity, decreases acidity and finally gives a soft and spongy finished idli.

Dated this 26th day of September 2018.