eChapters

SENSORY EVALUATION OF FOOD

When the quality of a food is judged or evaluated by the senses (taste, smell, sight, touch and hearing), it is said to be a sensory evaluation. Since food is prepared for the primary purpose of being eaten and enjoyed through the senses, sensory evaluation is most appropriate. No machine has yet been devised that can totally substitute for the human senses in evaluating the quality of human food. However, the human instrument used in sensory evaluation is very complex and many problems need to be managed as data are collected and analysed. Computers are generally used to analyse data from sensory evaluations and may also be used to collect information firsthand.

Flavour perceptions are difficult to characterise verbally, for example, think about how a strawberry tastes, then try to describe it some one else. In food research small groups of trained individuals called juding panels or sensory panels are commonly used to determine differences among food samples. These panels often consist of from 5 to 15 individuals who have had training and experience in testing the particular food products being evaluated.

Principles
The quality of foods can be defined as the ‘composite’ of those ‘characteristics’ that differentiate individual unit of a product and have significance in determining the degree of acceptability of that unit by the consumer. The overall quality refers to technological, physiological, chemical, microbiological, nutritional; and sensory parameters to achieve the wholesome food. Sensory quality attributes such as taste, colour, texture, flavour and overall quality of any food products were evaluated by 9- point Hedonic rating test is used for the purpose of evaluation. This test measures the consumer’s acceptability.

1. INTRODUCTION AND IMPORTANCE

Sensory evaluation is one of the important methods of evaluation of the quality of food. Without the sensory evaluation of a product whether it is fresh or processed, it cannot be launched in the market. All the other methods like physical, chemical and microbiological fails for the product development if sensory evaluation is ignored as the final acceptance can come from the sensory evaluation only. So sensory evaluation has got an upper edge as compared to the other methods of food quality evaluation. However, a collective approach of quality evaluation of a product that includes the physical, chemical, microbiological and sensory evaluation is the most acceptable approach today.

In the past, human sensory perception had been the only mean of assessment of product quality as illustrated by the classical examples of cooks who knew how to mask the off-notes long before the microbial assessment of quality came into existence. Everybody relied on the sensory evaluation of food as a criterion of quality assessment. In the past, even the kings depended upon “tasters” to assure that the food was suitable for their consumption in the past. The role of sensory organs in sensory evaluation of food is shown in Table 1. But later on, with the development of instrumentation, sensory analysis was overlooked and the instrumental methods were preferred as they were supposed to provide absolute measures of quality. Consequently, the product quality was traditionally determined by physical, chemical and microbiological criteria with the assumption that the products meeting the prescribed specifications in the above parameters would automatically meet the desired sensory quality. However, soon it was realized that without sensory evaluation, the acceptability of a product cannot be determined.

Introduction

Quality is the ultimate criterion of the desirability of any food product to the consumer. Overall quality depends on quantity, nutritional and other hidden attributes along with sensory quality. Sensory quality is of great importance to both processors and consumers, since it attracts consumers; it satisfies consumers’ aesthetics and gustatory sense. Sensory quality is the combination of sensory senses of perception responsible for choosing and eating a food.

According to Institute of Food Technologists and the American Society for Testing and Materials, sensory evaluation is a scientific method used to evoke measure, analyze, and explain those responses to products as perceived through different senses like sense of sight, smell, touch, taste, and hearing (Stone and Sidel, 2004). Sensory evaluation gives a general rule for the preparation and serving of samples under controlled conditions so that unfair decisions are minimized. People for sensory evaluation are often placed in individual test booths so that the judgments they give are true and do not reflect the opinions of those around them.

Samples with random numbers are given to the evaluators so that they do not form judgments based upon labels, but rather on their sensory experiences. Products may be given in different orders to each evaluator to help measure and to ensure internal validity by controlling the potential confounds created by sequence and order effects. To control unwanted variation and to improve test precision, standard procedures may be established for sample temperature, volume, and spacing in time, as needed.

Sensory evaluation or testing is a quantitative science in which numerical data are collected to establish lawful and specific relationships between product characteristics and human perception. Sensory methods draw heavily from the techniques of behavioural research in observing and quantifying human responses. For example, we can assess the proportion of times people are able to discriminate small product changes or the proportion of a group that expresses liking for one product over another. Another example is having people generate numerical responses reflecting their perception of products taste and smell.

Sensitivity-Threshold tests Sensitivity tests are conducted to assess the ability of individuals to detect different tastes, odors and feel the presence of specific factors in.

INTRODUCTION

A mixture is a combination of two or more elements or compounds in any proportion so that the components do not lose their identity. Most materials in our world are mixtures and very few materials are pure substances. Foods are complex mixtures of compounds and the extraction or separation of food components is fundamental for the preparation of ingredients to be used in other processes. Separations usually aim to remove specific components in order to increase the added value of the products, which may be the extracted component, the residue or both. Purposes include cleaning, sorting and grading operations, extraction and purification of fractions such as sugar solutions or vegetable oils, recovery of valuable components such as enzymes or flavour compounds, or removal of undesirable components such as microorganisms, agricultural residues or radionuclides. For example, cooking oils from oilseeds or gelatin from connective tissue; or for retrieval of high value compounds, such as enzymes (e.g. papain from papaya for meat tenderisation or rennet from calf stomachs for cheese making). Other types of separation methods are used to sort foods by separating them into classes based on size, colour or shape and to clean them by separating contaminating materials.

The various unit operations of food process engineering applied to solve the problem of changing the compositions of solutions, mixture and solids. Often these operations must be conducted on large scale to meet the demands of a large manufacturing plant. In food processes engineering these operations are often referred to as separation / concentration / extraction / purification process. Usually these operations are directed towards separating substances into its component parts or concentrating a particular substance from another.

Shelf life is a critical measure of ice cream quality and depends on formulation, processing, hardening, packaging, storage, and distribution conditions. This chapter explains the concept of shelf life and follows the movement of ice cream through the storage and distribution chain. It identifies temperature fluctuation and thermal abuse as major causes of quality deterioration, particularly through ice recrystallization and structural damage. The chapter examines hardening, formulation stability, cold-chain controls, shelf-life KPIs, and formal shelf-life studies. Common defects and their causes are also discussed. By understanding how temperature and handling influence product stability over time, manufacturers can establish better controls and protect texture, flavour, appearance, packaging integrity, and consumer acceptance.

This chapter introduces the commercial handling and processing of shell eggs from reception through packing. It examines pre-processing inspection, egg washing, cleaning, sanitization, drying, oiling, shell treatment, candling and defect removal. Automated grading and packing operations, plant layout, equipment, effluent management, sanitation and cleaning-in-place are also addressed. The chapter emphasizes traceability, good manufacturing practices and careful handling to prevent contamination and breakage. It demonstrates how packing stations preserve the quality delivered from the farm rather than creating quality after the fact.

HISTORICAL DEVELOPMENTS

Food Preservation 1782 ó Canning of vinegar was introduced by a Swedish chemist.

1810 ó Preservation of food by canning was patented by Appert in France. ó Peter Durand was issued a British patent to preserve food in ìglass, pottery, tin or other metals or fit materials.î The patent was later acquired by Hall, Gamble, and Donkin, possibly from Appert.

Abstract

This review assesses the nutritional attributes of Amaranth grains and its utilization as food and as formulated foods. Amaranth is a pseudo-cereal and one of the most ancient cultural food plants with excellent source of superior quality protein (rich source of lysine) which is deficient in wheat and other cereals. Amino acid composition of amaranth protein is close to ideal and, as a result, has high food value. Amaranth grain is loaded with phytochemicals including phenolic acids, tannins, anthocyanins, and phytosterols. Amaranth is potentially a good dietary source of the pro-vitamin A carotenoid (f-carotene), antioxidants (nutraceuticals) and canthaxanthin (which has also been reported to be an antitumor agent) and lutein, which is reported to slow down the development of age-related eye diseases. There are also some anti-nutritional factors (Phytic acid, Tannin and Trypsin inhibitor etc.) that may be reduced by certain processing treatments. Several epidemiological studies show Amaranth grains are helpful in reducing several kinds of chronic diseases like cancers, cardiovascular diseases, type II diabetes and various gastrointestinal disorders. Grain amaranth has been tested and recognised by many authorities as a gluten-free foodstuff appropriate for incorporation into the diet for celiac disease patients. Amaranth grain or young leaves could completely or partially substitute common ingredients, so the crop could be potentially exploited as an ingredient in foodformulation in form of flour, flakes, sprouts, grain undergoing fermentation, popping, malting, extrusion cooking, nixtimisation, and special compounds isolation. The interest in this crop is developing due to its several advantageous properties. The nutritionists find that the grain has higher nutritional value than conventional cereals.

Introduction

Our traditional knowledge of medicine has been one of the strongest areas of research because of our rich heritage in herbal plants & great biodiversity in our fauna & flora. Consumption of plant foods and the structurally diverse natural products provided by them have long been associated with health-protective and therapeutic effects. Natural products in plant foods have been shown to have pleiotropic therapeutic and chemopreventive properties. These bioactive products are known to potentiate the efficacy of other drugs and have synergistic effects too. Most of the prescription drugs discovered so far is from plant sources and 75% drugs had been claimed in folklore claims and traditional medicinal system (Reynold, 1991; Benowitz, 1996). The traditional Indian medicinal system utilizes multicomponent formulations of plant extracts which may either act synergistically or avoid many side effects and might have added up trace element through combination of different plant extracts which could have additive effects. However the effort to utilize traditional knowledge in the light of modern scientific findings is lacking in India. Accumulating evidences as well as in-vitro studies implicates inverse relationship between regular consumption of fruits vegetable and the risk of specific cancer. Diet derived nutritional compound mediated interventions in the process of tumorigenesis may be promising chemopreventive strategy with minimal toxicities to the physiological system.

5.1 Introduction

Food is the basic requirement of every living being and it provides physical, mental as well as emotional satisfaction. Globally, there are many food enterprises which provide this basic necessity across the nations irrespective of nature of origin and climatic condition. Food companies are required to provide products at certain quality parameters so as to maintain the uniformity in the food system. Hence, food quality can be defined as a total of traits and criteria which characterize food as regard to its nutritional value, sensory value, convenience as well as the safety for a consumer’s health. Food quality is the quality characteristics of food that is acceptable to consumers. This includes external factors as appearance (size, shape, colour, gloss and consistency), texture, and flavor; factors such as grade standards and internal (chemical, physical, microbial). Due to the various food risks, all over the world the quality regulation authorities have intensified the efforts to improve food quality. Some of the quality related systems are obligatory by law while other is voluntary which are to be implemented by the various food chain members.

Many companies are forced to improve safety and quality of their products by implementing the quality and safety assurance and management system because of growing consumers’ expectations and concerns as regards food quality and safety.

In order to attain maximum profit and decrease the flaws, a new system was developed and followed by various companies all over the world. This new system is known as Six Sigma. The application of this system has the capability to reduce the losses considerably by reviewing the process parameters and increasing the profit exponentially. It constitutes a systematic approach to assure that food products have particular traits at any stage of production and distribution.

Introduction
• Slaughtering of meat animals in way so as to effect minimum pain and suffering to animals is referred as humane slaughter
• Slaughtering method followed should inflict least stress and suffering to the animals
• There are acceptable and the unacceptable slaughtering methods and there is no ‘nice’ method to slaughter the food animals
• In advanced countries, common slaughtering method consists of two steps, stunning and bleeding
• Stunning is done to make animal unconscious and not to feel the pain during actual bleeding process which is followed next
• Exception of stunning-- Jewish and Muslim methods of slaughter
Stunning
Humane slaughter consists of stunning followed by sticking (bleeding). Stunning is the process of making the animal unconscious till it is slaughtered so that the pain suffered during actual act of slaughtering can be alleviated

Introduction

Smart farming focuses on retrieving data and using it in developing farming systems in a smart way that will yield better results. Such real time data can be readily accessed by the farmers through smart phones or tablets which will help them to take wise decisions at the right time. It helps in managing farms using technologies like IoT, robotics, drones and AI to increase the quantity and quality of products while optimizing the human labor required by production. Digital farming goes a step further and creates value from data. Integrating the concept of precision and smart farming, digital farming can be explained as “consistent application of the methods of precision farming and smart farming, internal and external networking of the farm and use of web-based data platforms together with Big Data analysis” (A paper on Digital Agriculture, 2018). Though such technologies are highly attractive and worth investing, they are also accompanied by uncertainty and trade – offs. Education, training, dissemination of information, finance and marketing are some of the major factors that would drive the farmers towards adoption of sustainable farming technologies (Grand View Research, 2019).

Introduction

Recent advances in food technology have made our lives virtually easier and efficient. Changing lifestyle has led to the emergence of packaged food that provides convenience to the consumers. The authentic packaging of food implements consumers with the role of communication, containment, convenience, and protection. Any typical food package provides us with the information about the product and its nutritional fact, thus an efficient way of marketing/ branding. It protects the food product from the external environment and adulteration, thus keeps it safe. It allows the consumers to relish the food as per their convenience (reheating and direct consumption) and holds the product of any size, shape and restrains during handling and transportation (Robertson, 2006).

Food packages can be altered or modified according to one’s requirement with features like single-serving dishes and portability. However, traditional packaging is lacking adequacy to meet unending consumer demands and product intricacies. Therefore, a contemporary concept of packaging with higher proficiency is needed to meet various consumer requirements. For instance, a packaging that can - enhance product’s shelf-life with lesser or no preservatives, that maintains freshness, that meets permissible regulatory requisites and enables tracking throughout the product life-cycle. Emerging technologies like smart packaging have the expertise to invigilate a product and its milieu and pursue any modifications into these. Moreover, smart packaging helps in gaining global market recognition, and meets international food safety standards. In recent years, there has been rapid development in food packaging that includes active packaging, intelligent packaging, or smart packaging. These are the technologies that deal with the packaging of food, beverages, cosmetics, and pharmaceutical products. Moreover, these terminologies are apparently identical but, each has a different function to deal with and is as follows:

Conventional fertilizers often exhibit low nutrient-use efficiency, resulting in nutrient losses, soil degradation, water contamination and unnecessary production costs. Nano-fertilizers offer controlled and targeted nutrient delivery through formulations engineered at the nanoscale. Their high surface-area-to-volume ratio can improve nutrient availability, plant uptake, growth, bulb quality and storage performance while reducing conventional fertilizer requirements. This chapter explains the nature, modes of action and potential benefits of nano-fertilizers in onion production. It also considers nano-biofertilizers, smart nutrient-delivery systems and nano-sensors. Particular attention is given to manufacturing cost, nanotoxicity, effects on soil microorganisms, farmer accessibility and the need for standardized safety and regulatory frameworks.

Efficient nutrient and water management is essential for achieving high onion productivity without degrading soil and water resources. Excessive fertilizer use, poor irrigation practices, groundwater depletion, nutrient imbalance and climate variability can reduce input efficiency and environmental sustainability. This chapter presents soil testing, integrated nutrient management, site-specific nutrient application, microbial interventions, residue management, nanotechnology and digital soil mapping. It also covers drip and sprinkler irrigation, scheduling, fertigation, mulching, rainwater harvesting and other water-conservation practices. Technologies such as SPAD meters, GreenSeeker, GPS, GIS, drones, remote sensing, sensors, artificial intelligence and IoT systems facilitate real-time monitoring, need-based application and climate-smart management of agricultural resources.

Smoking is an ancient method of food preservation, which is also known as smoke curing, produces products with very high salt content (>10%) and low water activity (~0.85). Smoking is a process of treating fish by exposing it to smoke from smouldering wood or plant materials to introduce flavour, taste, and preservative ingredients into the fish. This process is usually characterised by an integrated combination of salting, drying, heating and smoking steps in a smoking chamber. The drying effects during smoking, together with the antioxidant and bacteriostatic effects of the smoke, allow smoked products to have extended shelf-life. Smoked seafood includes different varieties like, smoked finfish and smoked bivalves. Many of the smoked products are in the form of ready-to-eat.

Developments of modern food preservation technology, such as pasteurization, cooling/refrigeration, deep-freezing, and vacuum packaging, have eclipsed the preserving functions of many traditional methods including smoking. Nowadays, the main purpose of smoking has been shifted for sensory quality rather than for its preservative effect.

Depending upon how the smoke is delivered into the food and smoking temperature, four basic types of smoking can be defined: hot smoking, cold smoking, liquid smoking, and electrostatic smoking. Hot smoking is the traditional smoking method using both heat and smoke, which usually occurs at temperatures above 70 °C. For smoked fish and fishery products, a minimum thermal process of 30 min at or above 145 °F (62.8 °C) is required by FDA (2001). Therefore, after hot smoking, products are fully cooked and ready for consumption.

Sodium benzoate is added to many fruit products to act as a preservative for the extension of the shelf life. Food Safety and Standards Regulations have specified the maximum level of sodium benzoate (Benzoic acid) in different products like sauce, ketchup, pickles, squash, etc. Therefore, the estimation of sodium benzoate (benzoic acid) in such products is considered a routine quality control procedure.
Principle
Benzoic acid which is sparingly soluble in water is converted into watersoluble sodium benzoate by the addition of NaOH in a sample containing sodium chloride solution. When the Sodium Benzoate solution is acidified with excess HCl, water-in-soluble benzoic acid is formed which is extracted with chloroform. The chloroform is removed by evaporation and the residue containing benzoic acid is dissolved in alcohol and then titrated with standard NaOH.