Prelim Notes_compressed

Food Spoilage Overview

  • Definition: Food spoilage refers to the changes in food that render it unsuitable for consumption by the consumer.

Types of Foods

1. Perishable Foods

  • Characteristics: High concentration of protein and water.

  • Examples: Fresh fruits, vegetables, dairy products.

2. Semi-Perishable Foods

  • Characteristics: Contain less water, edible for several months.

  • Examples: Canned goods, certain dried fruits.

3. Non-Perishable Foods

  • Characteristics: Very low water content, can be stored for several months with minimal quality loss.

  • Examples: Canned vegetables, dry grains.

Causes of Food Spoilage

Biological Changes

  • Microorganisms:

    • Bacteria

    • Yeasts

    • Molds

  • Impact: These organisms grow on food and lead to spoilage.

Chemical Changes

  • Enzyme Production:

    • Proteases, lipases, tyrosinase, polyphenol oxidase.

  • Impact: Enzymatic reactions lead to food degradation.

Physical Changes

  • Processes:

    • Evaporation

    • Drip loss

    • Separation.

  • Impact: Alter the texture and quality of food, contributing to spoilage.

Foodborne Illness

  • Definition: Illness transmitted to humans through foods.

Food Hazards

  • Types of Hazards: Biological, chemical, and physical.

Biological Hazards

  • Examples: Bacteria (e.g., Salmonella, E.coli), molds, viruses, parasites, prions.

Types of Foodborne Illnesses Due to Bacteria

1. Food Infection

  • Definition: Illness caused by consuming food contaminated with pathogenic microorganisms.

2. Food Intoxication/Poisoning

  • Definition: Illness caused by consuming toxins produced by microorganisms in food.

3. Toxin-Mediated Infection

  • Definition: Pathogen infects the gut; toxins produced during infection cause illness.

Chemical Hazards

  • Types:

    • Plant toxins

    • Animal toxins

    • Agricultural chemicals

    • Industrial chemicals.

Physical Hazards

  • Examples: Presence of foreign objects like glass, bone, metal, or plastic in food.

Prevention and Retardation of Food Spoilage

Safe Food Handling

  • Practices: Vital to ensure food safety and prevent spoilage.

Food Storage Conditions

  • Refrigerator: 4°C or below for consumers, 5°C for retailers.

  • Freezer: -18°C.

  • Dry Storage: 15-20°C for canned goods, 10-21°C for semi-perishables.

Temperature Danger Zone

  • Range: 4°C - 60°C for consumers; 5°C - 57°C for retailers.

  • Impact: This range is where bacteria grow rapidly and cause food spoilage.

Preservation Techniques

Dehydration

  • Definition: Removes at least 95% of water from foods, inhibiting microbial growth.

Freezing

  • Purpose: Makes water unavailable to microorganisms.

Fermentation

  • Process: Converts carbohydrates to carbon dioxide and alcohol by yeast/bacteria.

Food Safety Management Systems

Importance

  • Helps address food safety issues and maintain hygiene in food processing.

Prerequisite Programs (PRPs)

  • Definition: Basic conditions that ensure a safe and hygienic processing environment.

Key Principles of a Management System

  1. Customer-focused organization

  2. Leadership and involvement of people

  3. Process approach

  4. Continuous improvement

  5. Factual decision-making.

Standard Operating Procedures (SOPs)

Definition

  • SOPs are written instructions that document routine activities in a workplace.

Purpose

  • Roles of SOPs:

    • Provide clarity on tasks

    • Ensure consistency

    • Serve as training aids.

Key Elements of SOPs

  • Format: Title, edition number, issue date, author, introduction, scope, safety considerations, materials & equipment.

Effective Writing for SOPs

  • Guidelines:

    • Use simple language

    • Keep steps short

    • Refer to other SOPs as necessary

    • Avoid ambiguity and alternatives.

Common Components to Include

  • Title, edition number, issue date, author, introduction, safety considerations, and detailed procedural steps.