Description:FIELD OF THE INVENTION
The present invention relates to the field of food technology, fermentation science, and traditional food preservation. More particularly, the invention relates to a standardized, reproducible, and eco-friendly method for preparing 'Utong Ngari', a traditional fermented freshwater fish product of Manipur, using bamboo trunks (Dendrocalamus giganteus) as natural fermentation chambers, specific additives in precise proportions (10g salt, 5g sugar, 5ml mustard oil per kg fish), and a novel natural sealing system comprising pond mud and indigenous cow dung to ensure optimal anaerobic fermentation conditions. The invention bridges traditional knowledge systems with modern food science to produce a commercially viable, safe, and consistent fermented fish product.
BACKGROUND OF THE INVENTION
Traditional Context and Cultural Significance
Fermented fish products constitute an integral part of the dietary culture in Northeast India, particularly in Manipur, where they serve as a primary protein source and flavor enhancer. 'Ngari' and its variants, including 'Utong Ngari', have been consumed for centuries and hold significant cultural, nutritional, and economic importance. These products are not merely food items but represent the bio-cultural heritage of the region, playing crucial roles in traditional ceremonies, festivals, and daily cuisine.
Nutritional and Economic Importance
Fermented fish products provide essential amino acids, peptides, vitamins (particularly B12), and minerals. The fermentation process enhances bioavailability of nutrients and produces beneficial metabolites including organic acids, bacteriocins, and bioactive peptides. The market for traditional fermented fish products in Northeast India is estimated at several hundred crores annually, with significant potential for expansion if quality and safety can be assured.
Limitations of Traditional Methods
Traditional preparation methods vary considerably across households and regions, typically involving:
1. Inconsistent Processing Parameters:
o Variable fish-to-salt ratios (ranging from 3:1 to 10:1)
o Undefined fermentation periods (8-12 months)
o Lack of standardized container specifications
o Absence of controlled environmental conditions
2. Quality and Safety Concerns:
o Risk of pathogenic contamination (Clostridium botulinum, Staphylococcus aureus)
o Presence of biogenic amines beyond safe limits
o Inconsistent organoleptic properties
o Variable shelf life (2 weeks to 3 months)
3. Commercial Limitations:
o Inability to scale production
o Lack of reproducibility
o Absence of quality certification possibilities
o Limited market reach due to safety concerns
4. Technical Challenges:
o Uncontrolled fermentation leading to product spoilage
o Lack of understanding of microbial succession
o Absence of critical control points
o No standardized quality parameters
Scientific Gap
Despite the cultural importance and market potential, there exists a significant scientific gap in standardizing traditional fermentation processes while maintaining authentic characteristics. Previous attempts at modernization have either compromised traditional qualities or failed to ensure consistent safety standards.
STATEMENT OF INVENTION
The present invention addresses these challenges by providing a scientifically validated, standardized method that preserves traditional essence while ensuring consistency, safety, and commercial viability through innovative use of natural materials and precise process control.
PRIOR ART
Traditional Methods
1. Earthen Pot Fermentation (Regional Practice):
o Uses unglazed earthen vessels
o Variable capacity (5-50 kg)
o Inconsistent porosity affecting oxygen transfer
o Difficult to clean and sterilize
2. Bamboo Basket Methods (Southeast Asian Practice):
o Uses woven bamboo baskets
o Poor control of anaerobic conditions
o Susceptible to contamination
o Limited shelf life of products
Scientific Literature
1. Lee et al. (1993) - "Fish Fermentation Technology":
o Describes general principles of fish fermentation
o Focuses on Southeast Asian products
o Does not address bamboo trunk utilization
2. Thapa et al. (2004) - "Microbiology of Ngari":
o Identifies dominant microflora
o Uses earthen pot fermentation
o Lacks standardization protocol
3. Indian Patent Application No. 2018/DEL/2456:
o Describes fermented fish using plastic containers
o Requires addition of starter cultures
o Uses synthetic preservatives
4. Japanese Patent JP2005168422A:
o Fish fermentation using wooden barrels
o Requires temperature control (15-20°C)
o Not suitable for tropical climates
Distinguishing Features of Present Invention
None of the prior art discloses:
• Specific use of Dendrocalamus giganteus bamboo trunks with defined dimensions
• Precise additive formulation (10g salt, 5g sugar, 5ml mustard oil per kg)
• Novel pond mud and cow dung sealing system (1:1 ratio)
• Validated 4-month fermentation at ambient tropical temperatures
• Three-year replication data confirming reproducibility
• Complete absence of synthetic additives or starter cultures
• Metagenomics profiling of natural microbiota
• One-year validated shelf life
OBJECTS OF THE INVENTION
Primary Objects
The primary object of the present invention is to provide a scientifically standardized, reproducible method for preparing 'Utong Ngari' fermented fish product with consistent quality, safety, and extended shelf life.
Specific Objects
1. To utilize locally available Dendrocalamus giganteus bamboo as natural, biodegradable fermentation chambers with optimal dimensions (45 cm length, 10 cm diameter).
2. To establish precise proportions of natural additives (10g salt, 5g sugar, 5ml mustard oil per kg fish) that ensure optimal fermentation conditions and product characteristics.
3. To develop an innovative natural sealing system using pond mud and cow dung (1:1 ratio) that maintains strict anaerobic conditions throughout fermentation.
4. To standardize the fermentation period at 4 months under ambient conditions (20-35°C) suitable for tropical climates.
5. To produce a fermented fish product with consistent organoleptic properties including characteristic aroma, texture, and umami flavor.
6. To achieve microbiological safety with absence of pathogenic organisms and controlled biogenic amine levels.
7. To extend product shelf life to 12 months under normal storage conditions without synthetic preservatives.
8. To provide a method suitable for both household and commercial-scale production.
9. To preserve traditional knowledge while incorporating modern food safety standards.
10. To create economic opportunities for rural communities through value addition to locally available fish resources.
SUMMARY OF THE INVENTION
The present invention provides a comprehensive, scientifically validated method for preparing 'Utong Ngari', a naturally fermented freshwater fish product, through an innovative process that has been perfected over three years of systematic research and validation.
Key Innovations
The method employs bamboo trunks of Dendrocalamus giganteus (locally known as 'Maroobob') as natural fermentation chambers, specifically selected for their antimicrobial properties, optimal porosity, and structural integrity. The bamboo dimensions (45 cm length, 10 cm diameter) have been optimized through extensive trials to ensure proper fermentation dynamics.
The process utilizes sun-dried Puntius sophore fish, a locally abundant freshwater species, processed with a scientifically optimized additive blend comprising 10g salt (for selective microbial control), 5g sugar (as fermentation substrate), and 5ml mustard oil (for flavor and antimicrobial properties) per kilogram of fish.
Novel Sealing Technology
The invention introduces a breakthrough sealing technique combining:
• Aluminium tape for hermetic sealing of bamboo pores
• A bioactive sealing mixture of pond mud and indigenous cow dung (1:1 ratio) containing beneficial microorganisms
• External plastic wrapping for moisture retention and contamination prevention
Validation and Reproducibility
The method has undergone:
• Three years of systematic replication (36 production cycles)
• Comprehensive safety validation including pathogen testing
• Nutritional profiling showing enhanced amino acid content
• Metagenomics analysis revealing beneficial microbial succession
• Shelf life studies confirming 12-month stability
• Sensory evaluation by trained panels
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: Illustrates the complete step-by-step process of Utong Ngari production, showing:
• (a) Fresh Puntius sophore fish selection
• (b) Sun-drying process (3-5 days)
• (c) Bamboo trunk preparation and measurement
• (d) Additive mixing procedure
• (e) Fish stuffing technique
• (f) Sealing application method
• (g) Storage arrangement
• (h) Final product recovery
Figure 2: Detailed flowchart depicting:
• Critical control points (CCPs)
• Process parameters at each stage
• Quality checkpoints
• Time-temperature relationships
• Decision nodes for quality assurance
Figure 3: Product quality demonstration showing:
• (a) Consistency across multiple batches
• (b) Texture analysis results
• (c) Color development during fermentation
• (d) Final product appearance
• (e) Microscopic structure
• (f) Packaging options
DETAILED DESCRIPTION OF THE INVENTION
Preferred Embodiment
The present invention will now be described in detail with reference to the preferred embodiment, including specific process parameters, quality indicators, and validation data.
Stage 1: Raw Material Selection and Preparation
Fish Selection Criteria
• Species: Puntius sophore (Pool Barb)
• Size: 5-8 cm length, 10-15g individual weight
• Freshness: Caught within 6 hours
• Quality indicators: Clear eyes, firm flesh, absence of off-odors
• Seasonal consideration: Preferably pre-monsoon catch for optimal fat content
Cleaning and Pre-treatment
1. Wash fish in potable water (3 cycles)
2. Remove viscera if fish size >7 cm
3. Drain excess water (30 minutes)
4. Arrange on bamboo mats for sun-drying
Sun-drying Parameters
• Duration: 3-5 days (weather dependent)
• Temperature: 28-35°C
• Relative humidity: <60%
• Target moisture: 15-20% (measured by gravimetric method)
• Quality indicators: Firm texture, absence of fly infestation
Stage 2: Bamboo Trunk Preparation
Species Selection
• Scientific name: Dendrocalamus giganteus
• Local name: 'Maroobob'
• Age: 3-4 year old culms
• Harvest season: Post-monsoon for maximum strength
Dimensional Specifications
• Length: 45 cm (±2 cm tolerance)
• Internal diameter: 10 cm (±0.5 cm tolerance)
• Wall thickness: 1.5-2.0 cm
• Node retention: One natural node at bottom
Treatment Process
1. Cut bamboo at internode using sharp saw
2. Remove inner membrane carefully
3. Wash with 2% salt solution
4. Air dry for 24 hours
5. Inspect for cracks or pest damage and oiling inside the truck using mustard oil
Stage 3: Additive Formulation
Precise Measurements (per kg dried fish)
• Salt (NaCl): 10g (±0.1g)
o Grade: Food grade, iodized acceptable
o Function: Selective microbial control, water activity reduction
• Sugar (Sucrose): 5g (±0.1g)
o Grade: Refined white sugar
o Function: Fermentation substrate, flavor enhancement
• Mustard Oil: 5ml (±0.2ml)
o Quality: Cold-pressed, filtered
o Function: Antimicrobial, flavor, moisture retention
Mixing Protocol
1. Combine salt and sugar in sterile container
2. Add mustard oil gradually while mixing
3. Blend with dried fish using nitrile gloved hands
4. Ensure uniform coating (5 minutes mixing)
5. Rest for 15 minutes for absorption
Stage 4: Stuffing Process
Packing Technique
1. Layer 1 (Bottom): 2 cm thick fish layer
2. Compression: Apply gentle pressure (2-3 kg/cm²)
3. Subsequent layers: 3-4 cm each
4. Final compression: Ensure 80-85% chamber filling
5. Headspace: Maintain 3-4 cm from top
Density Optimization
• Target packing density: 0.65-0.70 g/cm³
• Prevents excessive compression
• Allows proper fermentation gas movement
• Ensures uniform fermentation
Stage 5: Advanced Sealing Technology
Polythene Barrier Layer
• Material: Food-grade LDPE, 50 micron thickness
• Sterilization: UV treatment for 30 minutes
• Placement: Direct contact with fish surface
• Function: Prevents contamination from sealing material
Aluminium Tape Application
• Specification: 50mm width, 0.08mm thickness
• Coverage: Complete bottom surface, 10cm up sides
• Overlap: Minimum 2cm between strips
• Function: Creates hermetic seal, prevents oxygen ingress
Bioactive Sealing Mixture Preparation
1. Pond Mud Collection:
o Source: Unpolluted freshwater pond
o Depth: 15-20 cm below surface
o Screening: 2mm mesh to remove debris
o Moisture adjustment: 40-45%
2. Cow Dung Specifications:
o Source: Indigenous cattle (Bos indicus)
o Collection: Fresh (<12 hours old)
o Pre-treatment: Homogenization
o Quality: Free from antibiotics, pesticides
3. Mixing Protocol:
o Ratio: 1:1 by weight (±5% tolerance)
o Mixing duration: 10 minutes
o Consistency: Thick paste (similar to putty)
o Application thickness: 2-3 cm layer
o Coverage: Complete top surface seal
External Protection
• Material: HDPE sheet, 100 micron
• Wrapping: 3 complete layers
• Securing: Cotton thread or adhesive tape
• Function: Moisture retention, contamination prevention
Stage 6: Fermentation Process Monitoring
Environmental Conditions
• Temperature Range: 20-35°C (ambient)
• Optimal Temperature: 28-30°C
• Relative Humidity: 60-75%
• Storage Location: Well-ventilated, shaded area
• Protection: From direct sunlight and rain
Fermentation Phases (Validated through metagenomics)
Phase 1 (Days 1-30): Initial Fermentation
• Dominant organisms: Lactobacillus plantarum, Pediococcus pentosaceus, Bacillus sp.
• pH drop: 6.8 to 5.5
• Lactic acid production: 0.8-1.2%
• Protein hydrolysis initiation
Phase 2 (Days 31-60): Active Fermentation
• Microbial succession: Bacillus subtilis, B. pumilus emergence
• pH stabilization: 5.5-6.0
• Protease activity: Peak levels
• Amino acid liberation: 40% increase
Phase 3 (Days 61-90): Maturation
• Complex flavor development
• Biogenic amine control
• Texture modification
• Volatile compound formation
Phase 4 (Days 91-120): Stabilization
• Microbial equilibrium establishment
• Final pH: 5.8-6.2
• Moisture stabilization: 38-42%
• Characteristic aroma development
Stage 7: Quality Assessment Parameters
Physical Parameters
• Texture: Semi-solid, easily spreadable
• Color: Light brown to amber
• Aroma: Characteristic fermented fish, absence of putrid odor
• Appearance: Uniform, absence of mold growth
Chemical Parameters
• pH: 5.5-6.5
• Moisture: 35-45%
• Salt Content: 2.5-3.5%
• Total Volatile Base Nitrogen (TVB-N):<35 mg/100g
• Histamine:<50 mg/kg
• Free Amino Acids: 15-20% increase from raw material
Microbiological Parameters
• Total Viable Count: 10⁶-10⁸ CFU/g
• Lactic Acid Bacteria: 10⁵-10⁷ CFU/g
• Pathogen Tests:
o Salmonella: Absent in 25g
o Staphylococcus aureus: <100 CFU/g
o Clostridium botulinum: Absent
o Escherichia coli: <10 CFU/g
o Listeria monocytogenes: Absent in 25g
Nutritional Profile (per 100g)
• Protein: 35-40g
• Fat:25-30 g
• Carbohydrate:10-12 g
• Ash:10-14 g
• Energy: 230-270 kcal
• Essential Amino Acids: Complete profile
• Vitamin B12: 8-12 μg
• Calcium: 800-1000 mg
• Phosphorus: 400-500 mg
• Iron: 8-10 mg
Stage 8: Product Recovery and Post-Processing
Opening Protocol
1. Remove external plastic carefully
2. Break mud-dung seal using sterile spatula
3. Remove polythene barrier
4. Extract fermented product using sterile tools
Packaging Options
• Traditional: Banana leaf wrapping
• Commercial: Food-grade plastic containers
• Premium: Vacuum-sealed pouches
Storage Recommendations
• Temperature: <30°C
• Relative humidity: <65%
• Protection from light
• Shelf life: 12 months (validated)
EXPERIMENTAL VALIDATION
Three-Year Replication Study
Year 1 (12 batches):
• Success rate: 91.6%
• Consistency score: 8.5/10
• Microbial safety: 100% pass
Year 2 (12 batches):
• Success rate: 100%
• Consistency score: 9.2/10
• Microbial safety: 100% pass
Year 3 (12 batches):
• Success rate: 100%
• Consistency score: 9.5/10
• Microbial safety: 100% pass
Comparative Analysis with Traditional Methods
Parameter Traditional Method Present Invention Improvement
Fermentation Period 8-12 months (variable) 4 months (fixed) Standardized
Product Consistency 40-60% 95-98% 58% increase
Microbial Safety 60-70% 100% Complete safety
Shelf Life 2-3 months 12 months 4x extension
Commercial Viability Low High Significant
Production Cost Variable Predictable 20% reduction
Sensory Evaluation
Trained panel (n=15) evaluation using 9-point hedonic scale:
• Appearance: 8.2 ± 0.3
• Aroma: 7.8 ± 0.4
• Texture: 8.5 ± 0.2
• Taste: 8.3 ± 0.3
• Overall Acceptability: 8.2 ± 0.2
Metagenomics Profile
16S rRNA sequencing revealed:
• Bacterial Diversity: Shannon index 3.8-4.2
• Dominant Genera:
o Bacillus (20-25%)
o Cetobacterium ceti(50- 60 %)
o Lactobacillus (5-10%)
o Staphylococcus (10-15%)
o Others (15-20%)
INDUSTRIAL APPLICABILITY
Commercial Scale-Up Potential
The method is suitable for:
1. Household Production: 5-10 kg batches
2. Cottage Industry: 50-100 kg batches
3. Small-Medium Enterprise: 500-1000 kg batches
Economic Analysis
• Raw Material Cost: ₹200-300/kg dried fish
• Processing Cost: ₹20-30/kg
• Packaging Cost: ₹10-15/kg
• Total Production Cost: ₹230-345/kg
• Market Price: ₹600-800/kg
• Profit Margin:>100-150%
Market Opportunity
• Regional Market: ₹500 crores (Northeast India)
• National Market: ₹2000 crores (potential)
• Export Potential: Southeast Asian diaspora markets
Employment Generation
• Direct employment: 2-3 persons per 100 kg daily production
• Indirect employment: Raw material supply chain, packaging, distribution
• Women empowerment: Suitable for women self-help groups
ADVANTAGES OF THE INVENTION
Technical Advantages
1. Reproducibility: Consistent results across batches (95-98% uniformity)
2. Scalability: Linear scale-up from 5 kg to 1000 kg
3. Process Control: Defined critical control points
4. Quality Assurance: Measurable quality parameters
5. Safety: Validated pathogen control
Environmental Advantages
1. Biodegradable Materials: 100% natural inputs
2. Zero Synthetic Chemicals: No preservatives or additives
3. Carbon Neutral: Bamboo sequesters CO₂
4. Waste Minimization: All by-products are biodegradable
5. Sustainable Resource Use: Renewable bamboo and local fish
Socio-Economic Advantages
1. Rural Development: Village-level production possible
2. Women Empowerment: Suitable for women entrepreneurs
3. Cultural Preservation: Maintains traditional food heritage
4. Import Substitution: Reduces dependency on preserved fish imports
5. Value Addition: 3-4x value increase from raw fish
Health and Nutrition Advantages
1. Probiotic Properties: Beneficial lactic acid bacteria
2. Enhanced Protein Digestibility: 30% improvement
3. Vitamin B12 Source: Addresses deficiency in vegetarian populations
4. Natural Preservation: No chemical preservatives
5. Bioactive Peptides: Antihypertensive and antioxidant properties

Methodology:

Figure 1. Steps involved in UtongNgari production

Figure 2. Flowchart of UtongNgaripreparation.

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Figure 3. Utong Ngari Products
, C , C , Claims:We claim:
1. A method for producing a fermented fish product known as 'Utong Ngari', comprising the steps of: a. selecting and preparing bamboo trunks of Dendrocalamus giganteus species having dimensions of 45 cm (±2 cm) in length and 10 cm (±0.5 cm) in internal diameter with one natural node retained at the bottom, wherein said bamboo is 3-4 years old and harvested post-monsoon; b. sun-drying fresh Puntius sophore fish of 5-8 cm length for 3-5 days at 28-35°C to achieve a moisture content of 15-20%; c. mixing the sun-dried fish with additives in the precise proportion of 10g (±0.1g) food-grade salt, 5g (±0.1g) refined sugar, and 5ml (±0.2ml) cold-pressed mustard oil per kilogram of dried fish, with mixing duration of 5 minutes; d. stuffing the fish-additive mixture into the prepared bamboo trunk in layers of 3-4 cm with gentle compression to achieve a packing density of 0.65-0.70 g/cm³; e. placing a layer of UV-sterilized food-grade LDPE polythene sheet of 50 micron thickness above the stuffed fish; f. sealing the lower and side sections of the bamboo trunk with aluminium tape of 50mm width and 0.08mm thickness with minimum 2cm overlap; g. applying a bioactive sealing mixture comprising pond mud from 15-20cm depth and fresh cow dung from indigenous cattle (Bos indicus) in 1:1 ratio to form a 2-3 cm thick layer on the top opening; h. wrapping the entire bamboo trunk with 100 micron HDPE sheet in 3 complete layers; i. fermenting the contents at ambient temperature of 20-35°C for a period of 4 months with monitoring of visual integrity; j. recovering the fermented product exhibiting pH 5.5-6.5, moisture 35-45%, and characteristic organoleptic properties.
2. The method as claimed in claim 1, wherein the bamboo trunk is derived from Dendrocalamus giganteus, locally known as 'Maroobob', treated with 2% salt solution and oiling and air-dried for 24 hours before use.
3. The method as claimed in claim 1, wherein the cow dung used in the sealing mixture is sourced from indigenous, non-farm cattle free from antibiotics and collected fresh within 12 hours.
4. The method as claimed in claim 1, wherein the fermentation proceeds through four distinct phases: initial fermentation (days 1-30) with pH drop to 5.5, active fermentation (days 31-60) with peak protease activity, maturation (days 61-90) with flavor development, and stabilization (days 91-120) with microbial equilibrium.
5. The method as claimed in claim 1, wherein the fermented product exhibits:
o Total Viable Count of 10⁶-10⁸ CFU/g
o Lactic Acid Bacteria count of 10⁵-10⁷ CFU/g
o Absence of pathogenic organisms including Salmonella, Clostridium botulinum, and Listeria monocytogenes
o Histamine content below 50 mg/kg
o Total Volatile Base Nitrogen below 35 mg/100g
6. The method as claimed in claim 1, wherein the process does not require any synthetic preservatives, artificial additives, commercial starter cultures, or controlled temperature conditions beyond ambient range.
7. The method as claimed in claim 1, wherein the fermented product retains microbiological safety, nutritional value, and organoleptic acceptability for up to 12 months under storage conditions of <30°C temperature and <65% relative humidity.
8. The method as claimed in claim 1, wherein the sealing mixture layer has a thickness of 2-3 cm and moisture content of 40-45%, providing both anaerobic conditions and beneficial microorganisms for fermentation.
9. The method as claimed in claim 1, wherein the fermented product exhibits enhanced nutritional profile with:
o Protein content of 35-40g per 100g
o Complete essential amino acid profile
o Vitamin B12 content of 8-12 μg per 100g
o 30% improvement in protein digestibility
o 15-20% increase in free amino acids
10. A fermented fish product 'Utong Ngari' prepared by the method as claimed in any of the claims 1-9, exhibiting consistent quality parameters across batches with 95-98% uniformity.
11. The method as claimed in claim 1, wherein the process is suitable for commercial-scale production ranging from 5 kg household batches to 1000 kg industrial batches while maintaining product consistency.
12. The method as claimed in claim 1, wherein the pond mud is collected from unpolluted freshwater sources at 15-20 cm depth, screened through 2mm mesh, and adjusted to 40-45% moisture content.
13. The method as claimed in claim 1, wherein the process achieves 100% microbial safety validation over 36 production cycles across three years of systematic replication.
14. The method as claimed in claim 1, wherein the bamboo trunk after preparation exhibits antimicrobial properties and optimal porosity for controlled fermentation.
15. The method as claimed in claim 1, wherein the method reduces production cost by 20% compared to traditional methods while achieving 4x extension in shelf life.