L8 Food Sensory Evaluation & Safety

Food Sensory Evaluation & Food Safety

• Food sensory evaluation is a scientific discipline used to measure and analyze people's responses to products, perceived through the five senses (sight, smell, touch, taste, and sound).
• A wide array of testing methods assesses sensory factors in food selection and quality evaluation.

Outline

• Sensory evaluation techniques include subjective and objective analyses.
• Subjective analysis evaluates food quality based on sensory attributes and personal preferences. It relies on selected individuals' opinions. Used to evaluate consumer preference for new or established products.
• Objective analysis quantitatively determines food quality through laboratory instruments, measuring physical and chemical differences.

Types of Subjective Analysis

• Analytical (Effective) Tests are more objective. Performed by trained panels, these tests differentiate food products (discriminative) or quantify differences (descriptive). Examples include triangle, duo-trio tests & ranking methods.
• Affective Tests are usually conducted for untrained consumers. They typically use simple questions or complex scales (e.g., 9-point hedonic scales) to assess preferences and attitudes towards food characteristics.

Taste Panels

• Taste panels consist of at least 5 people who meet specific criteria (free of colds, no gum/other food ingestion recently, no smoking, no color blindness, and no strong likes/dislikes for the food being tested).
• Panel members may include highly trained professionals or randomly selected members of the public.

Sample Preparation

• The environment for evaluating food should be carefully controlled.
• Panelists sit at uniform tables/booths.
• Food samples are uniform in size and from the same portion of the food, equally fresh, at the same temperature, presented in white or clear similar containers, and have consistent lighting.
• Ambient temperature should be comfortable, quiet, and odor-free. Ideal times are mid-morning or mid-afternoon.
• Sample coding is used, along with break periods, and provisions for spitting out samples.

Objective Analysis

• Laboratory instruments replace human subjectivity in objective evaluations, providing quantitative data.
• These methods are less time-consuming than sensory testing, giving more objective data, but cannot replace human sensory evaluations.
• They analyze harmful microorganisms, create quality control standards, and identify chemical components (e.g., nutrients, allergens, toxins) in foods.

Objective Evaluations (Physical Tests)

• Physical tests measure observable food properties, including size, shape, weight, volume, density, moisture content, texture, and viscosity.
• Selected laboratory instruments are typically employed to ensure products meet quality control standards.

Objective Evaluations (Chemical Tests)

• Many chemical tests exist for various food components.
• These tests are often based on standardization methods proposed by the Association of Official Analytical Chemists (AOAC).

Food Safety & Foodborne Illness

• Foodborne illness symptoms often involve gastrointestinal distress (inflammation, nausea, cramps, vomiting, diarrhea).
• The leading causes of foodborne illness include biological, chemical, and physical hazards.
• Biological Hazards: Common include microorganisms (bacteria, molds, viruses) and animal parasites (e.g., prions). Foodborne illness (bacteria via infection or intoxication) occurs when consuming food or beverage with large amounts of bacteria. Poisoning occurs when eating bacteria toxins.
• Chemical Hazards: These threats include plant toxins (e.g., poisonous mushrooms), seafood toxins, agricultural/industrial chemicals, or the presence of dangerous chemicals from plants (e.g., histamine).
• Physical Hazards: These include various foreign objects found in food.

Preventing Foodborne Illness

• Personnel: Staff training on personal hygiene practices (hand-washing, avoiding hand-to-mouth contact, use of uniform, etc.).
• Purchasing: Selecting high-risk foods (high protein and water content like meat, poultry, fish, dairy) requires careful inspection for quality control, and clear specifications.
• Storage: Correct temperatures are critical: Refrigerators (4°C), freezers (-18°C), and dry storage (15-21 °C / 10-21 °C).
• Preparation: Prevent cross-contamination and use appropriate thawing methods (e.g. refrigerator, running water, microwaving). Proper cooking temperatures to eliminate microorganisms.
• Cooling: Proper techniques are essential (shallow containers, ice water bath).
• Sanitation: Regular cleaning and sanitation procedures, proper use of equipment.
• Pest Control: Block any pest access and control infestations.