Question

Following the soxhlet procedure, calculate the % fat content on dry and wet basis
of a cheese sample considering the following:
Weight of dried sample = 2.0251 g
Weight of sample + thimble + glass wool = 5.4047 g
Weight of defatted sample + thimble + glass wool = 4.4107 g
% moisture = 35%

Answer 1

Ans. # Part 1: Mass of dried sample (cheese) = 2.0251 g

# Mass of fat = Loss in mass after running Soxhlet experiment

So, mass of fat = (Wt of sample + thimble + glass wool) – (Wt of defatted sample + thimble + glass wool)

                        = 5.4047 g – 4.4107 g = 0.994 g

# % fat (dry mass basis) = (Mass of fat / Mass of dried sample) x 100

                                                = (0.994 g / 2.0251 g) x 100 = 49.08 %

# Part 2: Given- moisture content in cheese sample = 35%

                        Mass of dried sample (cheese) = 2.0251 g

Let the mass of wet sample = X grams

So,

            X g – 35% of X g = 2.0251 g

            Or, X – 0.35 = 2.0251

            Or, X = 2.0251 / 0.65 = 3.1155

Hence, mass of wet sample = 3.1155 g

# Now,

            # % fat (wet mass basis) = (Mass of fat / Mass of wet sample) x 100

                                                = (0.994 g / 3.1155 g) x 100 = 31.90 %