Judging and and Grading

Good and acceptable quality food products are made by selecting good quality raw materials and following the established manufacturing techniques. This is also true with the manufacture of condensed milk and evaporated milk. Proper care should be taken to produce good quality product. Manufacturer should routinely examine the product to judge its quality and to maintain the grade that is acceptable to customers.

Judging refers to the act of evaluating the dairy product for its “Eating quality” on the basis of various attributes. Grading refers to its classification into different categories or grades. The eating quality of a dairy product is generally determined by organoleptic/sensory tests, which include all the five senses of sight, smell, taste,touch and sound. Of these taste and smell are the most important in judging and grading. There are various methods available for judging and grading of dairy products. Some of the subjective tests based on organoleptic examination such as flavour, taste etc. make use of the hedonic scale or variation of it.

i. Hedonic Scale: This method of rating for individual attributes is simple and gives a clear indication of the particular attribute of the product. For example the flavour of a dairy product may be evaluated on a hedonic scale rating from 1-10 points as suggested in the following Table Modification of hedonic scale using narrow range 1-5 may also be used in evaluating the product.

 

Hedonic scale for flavour

ii. Score card: The scorecards for condensed milk and evaporated milk proposed by the American Dairy Science Association (ADSA) were most useful in establishing standards and obtaining uniform high quality products

Score Card for Condensed Milk (ADSA)

Score Card for Evaporated Milk (ADSA)

These score cards considered such items as (a) flavour and odour; (b) body and texture; (c) colour; (d) fat content; (e) milk solids; (f) bacteria and (g) sugar in case of condensed milk only). Numerical values were assigned to each item. Flavour/ odour and body/texture were given higher ratings (30 and 25 points in case of condensed milk and 30 and 25 points in case of evaporated milk). Colour rated 5 points while all other items were treated equally being allotted 10 points each.

The following procedure should be followed for judging a product.

i) Sampling: Select a can of the product at random for examination.

Sequence of observations: Avoid undue agitation when transporting to the laboratory. Place it on the table for examination in the same upright position as before. Cut more than three fourths of the top of the can and turn it back.Then examine in the following order.

ii) Appearance of the can: Look for signs of rust etc., both outside and inside (when emptied).

iii) Appearance of the product: Examine uniformity of colour; look for absence of lumps in condensed milk and cream layer/butter/particles/curd in evaporated milk.

iv) Body and texture (viscosity): Observe whether the viscosity is high, normal or low while pouring the contents into a beaker.

v) Sediment: Watch for presence or absence of sediment at the bottom of the container when emptied.

vi) Flavour and odour: Note defects if any, by placing a small spoonful of condensed milk or diluted evaporated milk (1:1 with distilled water) on the tongue.

vii) Laboratory Tests: Take a sample aseptically and then test for fat, total solids,bacteria, sugar, adulterants and preservatives.

iii. Requirements for High Grade Condensed milk and Evaporated milk:The person who is judging the product should be familiar with the desirable qualities of the product as well as the possible defects, which may occur in both condensed milk and evaporated milk.

a) Condensed milk: It should have a clean, pleasant aroma, a pronounced sweet taste, smooth and uniform body and texture and uniform light colour, which should be yellow for cow milk and light greenish white for buffalo milk.

b) Evaporated Milk: It should have mild pleasant flavour, a relatively viscous body, uniformly smooth in texture and uniform colour.