Definition and Components of Food Quality

Definition: Quality is a measure of the degree of excellence or degree of acceptability by the consumer. It can be defined as “summary of features and characteristics of a product or service that bear on its ability to satisfy stated or implied needs”. In simple words the product should have attributes to “satisfy the wants/ needs of the consumer or conformance with the user’s requirements”. It also covers the safety and value for money. Food quality can be considered as

a complex characteristic of food that determines its value or acceptability to consumers. Thus it may be defined as “the composite of those characteristics which have significance in determining the degree of acceptability by the buyer. These characteristics should also have the ability to differentiate individual unit of the product.”

Components: The important components of food quality are: food safety, sensory characteristics and nutritional value. Safety of food is a basic requirement of food quality. “Food safety” implies absence or acceptable and safe levels of contaminants,adulterants, naturally occurring toxins or any other substance that may make food injurious to health on an acute or chronic basis. Besides safety, quality attributes include: nutritional value; organoleptic properties such as appearance, colour, texture, taste; and functional properties. The quality attributes are outlined in Table and includes primarily sensory attributes and hidden attributes. The sensory attributes include characteristics such as colour and appearance, viscosity and consistency, smell, taste, touch etc. The hidden characteristics are those which cannot be evaluated with human senses and yet are of real importance to human health and welfare. Nutritive value is one of the hidden characteristics, which is now considered by the consumers as a quality attribute. Adulterants and toxicants are the other hidden characteristics. Toxic substances may be of microbial origin, veterinary drugs residues, pesticide residues or heavy metals.

Classification of quality attributes

i) Food safety: In order to understand “food safety” we must first know the terms safe and hazard. “Safe” means that nothing harmful happens when we consume a food. A “hazard” is the capacity of a thing to cause harm. The objective of the food safety is to protect the food supply from microbial, chemical and physical hazards or contamination that may occur during all stages of milk production and handling-management of animals at farm, milk production, transportation,storage of raw milk, processing, production of value added products, distribution and storage of end products. It aims for keeping food wholesome and free from food borne illness. The important associated definitions and factors are described for better understanding of the food safety.

(a) Food borne illness: Food borne illness or food poisoning is caused by consuming food contaminated with pathogenic bacteria, toxins, viruses or parasites. The contamination may or may not alter a food’s organoleptic properties but cause illness and disease to human beings after consumption and usually arises from improper handling, preparation or storage of food.Food-borne diseases are classified as food infections or food intoxications. Food infections involve microorganisms present in the food at the time of consumption which then grow in the host and cause illness and disease.Food intoxications involve toxic substances produced in foods by microorganisms prior to consumption and cause disease upon ingestion.The toxin producing microorganisms need not to grow in the host to produce a disease or even be present in the food. So we must acknowledge that intoxication can occur even if no viable microorganisms are ingested.

(b) Food hazards: Food becomes hazardous by contamination. Contamination is the unintended presence of harmful substances or microorganisms in food. Food hazards can be defined as a biological, chemical or physical agent in a food, with the potential to cause an adverse health effect (Table). Physical hazards are foreign particles, like glass/wood or metal pieces, stone, bone fragments, feathers, fibre, hair, etc. Chemical hazards include substances such as cleaning solutions and sanitizers, non permitted adulterants, pesticide and heavy metal residues. Biological hazards come mainly from microorganisms. The Directorate General of Health Services

Quality (DGHS), Ministry of Health is pursuing a broad and long-term sciencebased strategy to improve the food safety and to better protect the public health. Part of this strategy is a farm-to-table approach to improve the safety of food at each step in the food production, distribution, and marketing chain. The website (http://foodsafetyindia.nic.in) gives a good diagrammatic account of potential hazards and guidelines for food safety at home. One of the interesting terms used is “FAT TOM”. It is a term that in short explains what encourages food borne pathogens to grow i.e.F is for Food or nutrients present; A is for Acidity; T is for time; T is for Temperature; O is for oxygen and M is for Moisture.

Hazards associated with food

Source: Food Safety- Basic Concepts

 (c) Food Safety Management Systems Certification(FSMS): The Bureau of Indian Standards (BIS) has launched Food Safety Management Systems (FSMS) Certification IS/ISO 22000:2005 scheme which envisages grant of FSMS Certification licence to organizations according to IS/ISO 22000.This standard integrates the principles of Hazard Analysis and Critical Control Point (HACCP) system developed by Codex Alimentarius Commission and combines the HACCP plan with Pre-requisite Programmes (PRPs) and is fully compatible with Quality Management Systems (QMS) as per ISO 9001: 2000. The standard provides framework for systematically managing safety in food supply chains.

(d) The Food Safety and Standards Act, 2006: The chapter six of the Act titled as “Special Responsibilities as to Food Safety” deals with responsibilities of the food business operator, liability of manufacturers, packers, wholesalers, distributors and sellers and recall procedures.

(e) Safety concerns: We know that the goal of food safety is to reduce the size of risks to the lowest reasonable level without severe disruption of the food supply. For this we should first identify hazards related to foods or food components and then estimate the size of the risk that the hazard will cause. It is important to note that all foods have some degree of risk and that no food is absolutely “safe.” The important consideration becomes “the size of the risk and how the size of the risk can be reduced” without eliminating the food source. Specific food safety concerns differ markedly and include: 

•  Additives, colours and flavours.
•  Antibiotics and other food additives.
•  Fertilizers and other growing aids.
•  Irradiation.
• Microbiological contamination.
•  Naturally occurring food toxicants.
•  Nutrition.
•  Pesticides.
•  Pollutants.
•  Processing, packaging and labelling.
•  Tampering.

 (f) Adhering to Safety Standards: The advantages associated with adhering to food safety standards are:

•  Ensures safety of food products.
•  Greater health protection.
•  Increased international acceptance of food products.
•  Helps to meet applicable food safety related statuary & regulatory requirements.
•  Demonstrate conformance to international standards and applicable regulatory requirements.
•  Reduces risk of product/service liability claims.

 (g) Recent Concerns of Food Safety: Prions, genetically modified foods, the incidence of bovine spongiform encephalopathy (BSE), and dioxincontaminated foods are some of the new food safety concerns. Let us know about them.

Prions are one of the new sources of food borne diseases. A prion is the short form of proteinaceous infectious particle. Dr. Stanely Prusiner coined the word “prion” as a name for the infectious agent, by combining the first two syllables of the words “proteinaceous” and “infectious.” While the infectious agent was named a prion, the specific protein that the prion was made of was named PrP, an abbreviation for “protease-resistant protein”.The normal form of the protein is called PrPC, while the infectious form is called PrPSc, which stands for prion protein of scrapie. Prions are generally quite resistant to denaturation by protease, heat, radiation, and formalin treatments, although potency or infectivity can be reduced. Prions enter cells and apparently believed to infect and propagate by refolding abnormally into a structure which is able to convert normal

Quality molecules of the protein into the abnormally structured form. The proteins accumulate in the brain causing holes or plaques and the subsequent clinical symptom leading to death.Prion diseases are grouped as transmissible spongiform encephalopathy (TSE). The diseases associated by prisons are: Creutzfeldt-Jakob Disease (CJD), Bovine spongiform encephalopathy (BSE- commonly known as “mad cow disease”), fatal familial insomnia and kuru (translated as “to tremble with fear”).

Bovine Spongiform Encephalopathy (BSE): Bovine Spongiform Encephalopathy is commonly known as mad- cow diseases. It is a progressive neurological disorder (brain disease) of cattle that results from an infection by an unconventional transmissible agent. BSE is one of a transmissible Spongiform Encephalopathies (TSEs) that affect a number of different mammals.

Creutzfeldt-Jakob Disease (CJD): It is one of the most commonly known diseases among humans. This is a rare and fatal form of dementia and mainly occurs in individuals between the ages of 40 and 80.

Dioxin–Contaminated Foods: Dioxin is the popular name for the family of halogenated organic compounds, the most common consisting of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-pdioxins (PCDDs). PCDD/PCDFs are industrial pollutants that persist in the environment. They have been shown to bio accumulate in humans and wildlife due to their lipophilic (fat loving) properties. Dioxins are a carcinogen in higher amounts, and cause developmental and reproductive problems. They are absorbed primarily through dietary intake of fat, as this is where they accumulate in animals, including humans.

Genetically Modified (GM) Foods: The GM foods are produced from genetically modified organisms (GMO). A GMO means: an organism that has been modified (manipulation of DNA) by gene technology. Genetically modified (GM) crops and food are being grown and consumed by the public. The advantages associated are: increased yields from agriculture,more powerful control of pests and weeds, reduced use of some agrochemicals and enhancement of nutritional value or other characteristics of crops, etc. There are many things which people hold up as possible dangers of genetic modification: risk of transferring crop traits to wild species, negative impacts on wildlife from more powerful control of pests and weeds, increased use of some agrochemicals, increased corporate control of seed supply and; limited studies on food safety concerns on human health in form of toxins/ allergenic reactions/ reduction in good micro flora of duct, etc.

ii) Nutritional Value: Nutritional value of the product has grown in importance as consumers have become better informed about foods. The consumers demand for nutritional labelling in addition to food safety. Nutritional changes occur in foods during handling, processing and storage due to microbiological, enzymatic and chemical reactions. One of the principal responsibilities of the dairy technologists is to preserve nutrients through all phases of food acquisition,processing, preparation and storage. As a food processor, we should have good knowledge of the stability of nutrients under different conditions. Vitamin A is highly sensitive (i.e., unstable) to acid, air, light, and heat; on the other hand,vitamin C is stable in acid but is sensitive to alkalinity, air, light, and heat. Because of the instability of nutrients under various conditions and their water solubility, cooking losses of some essential nutrients may be greater than 75%. In modern food processing operations, however, losses seldom exceed 25%. The food should not contain any toxic/ anti- nutritional substances.

iii) Sensory Characteristics: The sensory characteristics of foods and materials are based on perception of human senses i.e. senses of sight, smell, taste, touch and hearing. The sensory evaluation of milk and milk products has been covered extensively in the next block i.e. Block 3 of this course. Some of the attributes are described below:

Colour and Gloss: Colour is the property, which is based on the spectral distribution of light. The white colour of milk is due to the reflection of light by the casein micelles dispersed in the continuous phase/ dissolved phase of water and yellow tinge in cow milk is because of the presence of â-carotene in it. Similarly the glossiness, transparency, haziness and turbidity are the

properties of substance due to the differences in reflectance and transmittance of light. Spectrophotometer is the instrument used for measuring of colour intensity while turbidity meter is used to measure turbidity.

Viscosity/ Consistency: It has great importance in liquid products such as fluid milk products or semisolid products like condensed milk, ice-cream, rabri, lassi, etc. Consumers judge the richness of these products by viscosity/consistency characteristics. These can also be used as an index to the concentration of ingredients.

Size and Shape: Grading into various size and shape categories is usually one of the first steps in food processing operations of fruit and vegetables.For milk products it can be applied in case of sweets like Rasogulla, Gulabjamun, etc.

Texture: Texture is the most important property of most of the milk products such as Rasogulla, Paneer, Chhana, Khoa, Ice-cream, Butter, Ghee,Gulabjamun, Peda, Burfi etc. There are several instruments available to measure texture attributes of these products in the form of cohesiveness,

chewiness, gumminess mealiness, stickiness, etc.

Flavour: Flavour includes taste and odour/ aroma. Like texture the flavor is also very important attribute of the milk and milk products. Even it is much more important than texture in some of the products like ice-cream. An icecream will be rejected if it does not have pleasing flavour even if it is otherwise good.