BSI Education

Integrated Assignment 02

Quality control in food processing

Quality control is important for any food processing business. The quality of the supplies and the quality of the final products all need to be controlled.

A food manufacturer has to obtain ingredients that are of the right quality for the production process. This is done by agreeing on a set of standards with each supplier. Then the manufacturer needs to have a system in place to sample the supplies and check that they meet the agreed standards.

It is also important for the manufacturer to have quality checks on the food that is produced. It has to meet the standards required by food safety and consumer protection laws. It must also meet the producer’s own standards for that product.

The quality of foods and food ingredients can be measured in many different ways. In general, quality control measurements should be as simple as possible and only give the information that is needed. Too much information can hide important points.

Your assignment

A food processing company is adding a new pickle to its product range. A quality control program needs to be set up for the process. Three important areas have been identified as critical points for quality control:

  • the ripeness of the tomatoes and apples, and the crispness of the carrots and cucumbers;
  • the strength of the vinegar;
  • the keeping quality of the final pickle.

Your assignment is to devise quality control procedures for each of these critical areas and to decide on acceptable limits for the measurements made.

What you have to do

Quality control for the fruit and vegetables

  1. Draw up a table that lists the features of the tomatoes that are important for the quality of the pickle. (Read What you need to think about.) Consider how to set limits that will decide whether tomatoes are accepted or rejected. For example:
Feature Accept Reject
Mould growing on skin Clear of all mould Any visible mould
     
     
  1. Decide what tests or measurements are necessary for good quality control.
  2. Where necessary, devise standard procedures to make these measurements.
  3. Write down instructions for the standard procedures.
  4. For each procedure, measure a selection of tomatoes, and decide on the quality standard required. Fill this in on the table.
  5. Do steps 1 - 5 for each fruit or vegetable to be considered.

Quality control for the vinegar

  1. Read What you need to think about and decide what tests or measurements are necessary for good quality control of each batch of vinegar supplied.
  2. Where necessary, devise standard procedures to make these measurements.
  3. Write down instructions for the standard procedures.
  4. Use the procedures to test several different sources of vinegar. Decide on an acceptable quality standard.

Keeping quality of the final product

  1. Test some samples of a good quality pickle. Using steps 12 - 13, count the micro-organisms present in the fresh product and after storage in an open dish at room temperature for different periods.
  2. Use a sterile measuring spoon to put 15 cm3 of pickle into a small sterile beaker. Add an equal measure of sterile saline-peptone. Mix gently without breaking the vegetable pieces.
  3. Remove a sample of the liquid to a sterile bottle. Keep refrigerated and test as soon as possible using Standard Procedure SP 0003:2005.
  4. Use your results to decide the conditions and acceptable results for a quality control test for each batch of pickle produced.

What you need to think about

  • Vegetable quality checks might include size, shape, colour, blemishes and damage, mould, ripeness, freshness. Remember not to include unnecessary tests. Consider only what is important for the quality of the pickle.
  • Apples and tomatoes for making pickle need to be ripe to give the right flavour and sauce consistency. Ripe fruit have different colour and hardness from unripe fruit. Consider how SP 0012:2005 Methods of testing strengths of materials could be adapted to help test the ripeness of tomatoes or apples.
  • Crisp vegetables are important to give the pieces in the pickle a good texture. Consider how to test the crispness of cucumbers or carrots. A rough test for the crispness of a carrot or cucumber is to break it in half. A fresh carrot will break cleanly, a stale carrot will bend before it breaks. Fresh vegetables may show a different compressive strength than stale samples of the same vegetable.
  • The quality of the vinegar used to make the pickle is important. The colour and clarity can be seen, but it is the acidity of the vinegar which inhibits the growth of micro-organisms and creates a product that will keep well at room temperature. The acid in vinegar is ethanoic acid. The amount present in vinegar can be determined by titrating diluted vinegar against a standard solution of sodium hydroxide. All measurements must be made accurately. Use a 0.100 mol dm-3 solution of sodium hydroxide in the burette. Dilute the vinegar by pipetting 25.0 cm3 of vinegar into a volumetric flask and making it up to 250 cm3 with distilled water. Titrate 25.0 cm3 of the diluted vinegar against the sodium hydroxide using 3 - 4 drops of phenolphthalein solution as indicator. Titrate until a slight pink colour remains for about 15 seconds. Calculate the average of several titrations. This value multiplied by 0.24 gives the percentage of ethanoic acid in the undiluted vinegar, i.e. its concentration in g per 100 cm3.
  • Keep all procedures as simple as possible. Only include the quality checks that are necessary for this product. For example, the size of tomatoes will not matter as they form a sauce, but the ripeness is important. Consider the likely faults that could cause problems.
  • Use the quality checks and standard procedures on several samples before deciding on the limits of acceptable values.

Remember: You should never eat food in a laboratory.

Presenting your conclusions

Present your conclusions as a list of quality checks necessary in the three critical areas of pickle production. For each check there should be a clear indication of what should be accepted and what should be rejected. Include details of any standard procedures that are necessary to carry out the quality controls.

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