During processing of food, heat penetration is an important factor and it should be known to ensure that every particle of food within the container receive the required heat treatment. If the cans are heated from outside, larger the can, larger time it will take to heat the center portion of can to any desired temperature. However, there are several factor besides size and shape of can that affect the heat penetration into food within it.
Liquid food such as canned tomato juice can be readily set into convection heating motion after receiving heat by conduction from the wall of the can. On other hand, solid food such as canned beef hash is too viscous to circulate and so it will be completely heated by conduction through the can wall and through itself. A product containing a combination of free liquid and solid such as can of peas within a sugar syrup will be intermediate and will rise in temperature from the combination of conduction and convection. Convection heating is more rapid than conduction heating.
Methods of heat Penetration
During thermal processing, contents of the can is heated by following methods; Read more
The term quality attributes includes all the factor that influence product’s value to the consumer. Quality attributes can be positive or negative. Negative attributes includes spoilage, contamination, discoloration, off odor etc. while positive attribute includes safety, nutrition, flavor, color, texture, suitability of processing etc. quality attributes of food can be well described by following classification.
Quantitative attribute: It is important from standpoint of both traders and ultimate consumers. It is expressed as proportion of ingredients net weight, drain weight etc.
Hidden attribute: It implies suitability of product from standpoint of health and which consumers cannot evaluate through their own sense. It includes safety and nutritional factors.
sensory attributes: It is based on consumer’s preferences perceived by their senses. This includes appearance, kinesthetic factor and flavor factor.
Factor Influencing sensory attributes
Appearance factor
It is an eye appeal judged by sense of sight. Such as,
a) Size and shape wholesomeness: It can be easily perceived by eyes. However, for accuracy and standards, devices such as screen, scale, micrometer etc. are used. For shape, weight/volume ratio, symmetry, length/width ratio, curvature area etc. are measured.
b) Size and shape wholesomeness: It can be easily perceived by eyes. However, for accuracy and standards, devices such as screen, scale, micrometer etc. are used. For shape, weight/volume ratio, symmetry, length/width ratio, curvature area etc. are measured.
c) Defects, damage, extraneous matter: Defects are imperfections due to presence of something unwanted. Defects may include
Insect damage or injury (bruising, crushing)
Extraneous matter or foreign matter. Extraneous matter might be harmless but not part of edible portion. Such as eyes in canned pineapple slices
Deformed shape of fruits and vegetables (due to environment or genetic factor) or other processed food (due to fault in processing).
Spectral: This includes color, gloss, transparency, turbidity etc. color and gloss are attributed to spectral distribution of light. Transparency, haziness and turbidity is attributable to absorbance or transmittance of light by the material.
Consistency: This includes viscosity, gel flow and spread. Major quality attributes with food such as ketchup, juice, cream, jam marmalade, syrups etc. viscosity is resistant force to deformation when subjected to shearing force. Measurement of viscosity not only indicate consistency of final product but also quality control tools applied for raw material and during processing to obtain desired final product.
Kinesthetic factor
It is judged by sense of touch such as hand feel (firmness, softness, juiciness, grittiness) and mouth feel (chewiness, fibrousness, grittiness, mealiness, stickiness). Kinesthetic attributes or texture is the way in which structural components of food are arranged in micro or macro structure and the external manifestation of these structure. It includes qualities of food that can be felt with tongue, palate or teeth. The range of texture is considerable and departure from expected texture is a quality defect. Take for example; apples are expected to be firm, mango and plum to be soft, sweet corn to be juicy and potato chips to be crisp.
Physical instruments can also be applied to simulate and measure the sensation which the consumer experiences (kinesthetic attributes) such as texture analyzer, viscometer etc.
Flavor factor
It Is judged by sense of taste and smell. It includes sense of odor such as fragrance, acid and burnt, sense of taste such as sweet, sour, salty and bitter and sense of off-flavor such as enzymatic, physiological, chemical, contamination, overcooked etc. Flavor attributes are evaluated by consumers with the sense of taste and smell. The term flavor indicates four basic taste and aroma received through tasting. There are four basic taste and are sensed by different receptor sites of tongue.
Sweet:
tip of tongue
Salt:
tip and edge of tongue
Sour:
edge of tongue
Bitter:
back of tongue
Fig. 1: Total flavor impression of food
Desirable flavor in food is a positive quality attributes which can be retained in food by
Prevention of loss of desirable flavor during heat treatment, handling, transport and storage.
Avoidance of development of undesirable flavor. Example, oxidative rancidity in fat and oil and metallic flavor in canned products.
Development and preservation of desirable flavor as in roasting coffee bean, baking bread, aging wine etc.
Fortification of food with natural flavors that are lost during processing.
About Author
Name : Pratiksha Shrestha
pratiksha.shrestha2001@gmail.com
Ms. Shrestha holds masters degree in food engineering and bioprocess technology from Asian Institute of Technology (AIT) Thailand. She is currently working for Government of Nepal at Department of Food Technology and Quality Control (DFTQC), Kathmandu. She is also a teaching faculty in College of Applied food and Dairy Technology (CAFODAT) affiliated to Purbanchal university, Nepal.
To the basic understanding, quality is the combination of characteristics of the product that are significant to determining the degree of acceptability of the product to the customer. According to sir Edwards Deming, quality should be aimed at customer present and future. Therefore, it can be said that quality is degree of goodness marked by consumers / customers. The quality is relative term and it is said to be met when goods and services are analyzed on basis of both consumers and producers perspective.
Quality is grade or distinguishing feature of the product.
Quality is degree of preference.
Quality is degree of excellence.
Quality is conformity to requirements.
2. Quality Control:
One of the approach of improving quality of the product is implementing quality control. It is an operational technique and activities that are used to fulfill requirements for quality. it consists of corrective tools that are reactive in nature. The quality control tools help to find faults in the product or services and take necessary action to deliver good quality product or services.
3. Quality Assurance:
For better quality system, quality assurance is important. Quality assurance is a planned and systematic activities implemented to provide adequate confidence that product or services will fulfill requirements for quality. It is a system implemented by an organization which assures outside bodies that data generated is of proven and known quality and meets the need of end user. This assurance relies heavily on documentation of process, procedures, capabilities and monitoring of such.
Quality assurance refers to the process used to create the deliverables and can be performed by a manager, client or even a third-party reviewer. For example, quality assurance includes process checklist and project audit. If the project is audited, the auditor might not be able to tell if the specific deliverable is acceptable. However, auditor should be able to tell if deliverable seem acceptable based on the process used to create it. This is why project auditor can perform quality assurance review because it is about knowing about how good process looks like. Quality assurance uses various tools such as bench marking, flow chart, cause and effect chart. Widely used approach for quality assurance is Plan – Do – Check – Act (PDCA) cycle.
Plan: Establish new objective and process necessary to deliver results in accordance with expected output.
Do: Implement the new process. Often small scale if possible
Check: Measure the new process and compare the result
Act: Analyze the difference and determine where to apply the changes to make improvement
4. Which comes first, Quality Assurance or Quality Control ?
Quality assurance is more effective in maintaining quality of any product or service. Quality control is product-oriented activity and quality assurance is process oriented activity. Without assuring quality of process, quality product cannot be achieved. Quality assurance is a broad approach which refers to the process used to create deliverables and can be performed by manager, client or even third-party reviewer. Whereas QC is focused on only deliverable itself and conducting QC needs technical skill. QC is about finding defect during or after the product development and correcting them whereas QA is meant to produce defect free goods and services which means being right for first time with no or minimum rework. However, both quality control and quality assurance is equally important for managing overall quality in the system and both need to be implemented for achieving quality goals of the institution.
About Author
Name : Pratiksha Shrestha
pratiksha.shrestha2001@gmail.com
Ms. Shrestha holds masters degree in food engineering and bioprocess technology from Asian Institute of Technology (AIT) Thailand. She is currently working for Government of Nepal at Department of Food Technology and Quality Control (DFTQC), Kathmandu. She is also a teaching faculty in College of Applied food and Dairy Technology (CAFODAT) affiliated to Purbanchal university, Nepal.
