ABSTRACT

This study investigates the impact of different coagulants on the chemical composition and sensory evaluation of cottage cheese and cream cheese. The research was conducted at the Department of Animal Science laboratory, University of Benin, Benin, city, Nigeria, and Quality Analytical laboratory Ltd, KM 8, Benin/Lagos express road, Benin city, Nigeria. The coagulants used were vinegar (T1), lime juice (T2) lemon juice (T3) and unripe pawpaw pulp (T4). The materials: milk, lime, lemon, vinegar and pawpaw, were sourced locally from Ovia North-East Local Government Area of Benin city, Edo state, Nigeria. The juice was extracted from the lemon and lime fruits using a juice extractor while the extract from the unripe pawpaw pulp was obtained by blending the pulp with water and straining the slurry to collect the water. The four coagulants were used to prepare samples of each cheese variant resulting in four samples of cream cheese and four samples of cottage cheese. Triplicates were taken for chemical analysis using standard AOAC procedures for chemical analysis. The sensory evaluation was conducted with questionnaires designed with a 5-point hedonic scale ;1- Very poor, 2- Below average, 3-Average, 4-Above average and 5-Excellent. Twenty (20) evaluators tasted and graded the cheese samples.

The results indicated significant variations (P<0.05) in the chemical composition of the cheese variants, depending on the coagulant used. In cottage cheese samples, moisture content ranged between 54.60–61.67% with T4 and T3, having the highest and lowest values respectively with significant variation (P<0.05) across all samples. There was significant variation (P<0.05) across all samples in ether extract content with T1 having the highest ether extract value (11.83%) and the lowest was T4 (8.74%). Significant variation (P<0.05) was observed in protein and nitrogen free extract content across all samples. Ash content of T2 (1.97) and T3 (2.02%) and had no variation (P>0.5) between them although the other samples had significant variations (P<0.05). For cream cheese, the highest values for moisture, ether extract, crude protein, ash content, and nitrogen free extract were T3. (69.29%), T1 (11.67%), T3 (10.57%), T2 (1.29%) and T2 (19.58%) respectively. Lower values were observed for the same parameters in; T2 (64.20%), T4 (7.15%), T4 (6.32%), T3 (1.10%) and T3 (9.83%) respectively. Moisture content and ether extract showed significant differences (P<0.05) across all samples. Crude protein, ash and nitrogen free extract had significant difference (P<0.05) but not across all samples. These results show an increase in fats (3.5%) and protein (3.5%) contents present in the milk before it was processed into cheese. This was also observed in the mineral composition of cream and cottage cheese. For calcium (Ca) in cream cheese there was significant variation (P<0.05) between T2 and other samples, the highest values were seen in T1 (160.3 mg/100) and T2 (146.5 mg/100) had the lowest value. In cottage cheese significant variation (P<0.05) was observed in other samples except T1 and T3. The highest values were observed in T4 (603.00 mg/100) and the lowest in T1 (254.20 mg/100). Phosphorous (P) had significant variation (P<0.05) for both cottage and cream cheese. The values were high in T4 (153.00 mg/100) for cottage cheese and T3 (95.91 mg/100) for cream cheese. T2 reported the lowest values for both cottage cheese and cream cheese. Zinc (Zn) content in T2 of cottage cheese was significantly different(P<0.05) from all other samples while in cream cheese, T4 was significantly different (P<0.05) from T1 and T2. The reported calcium and phosphorus content are higher than the initial contents found in the milk (Ca=117.4 mg/100, P=114.8 mg/100). The sensory evaluation revealed no significant variation (P>0.05) Between cottage cheese samples. T2 had high values for appearance (3.40), smell (3.80), taste (3.055), texture ((3.20) and acceptability (3.15). T4 had low values in appearance (3.15), smell (3.45), texture (3.00) and acceptability (2.90) while T3 had the lowest value for taste (3.00). For cream cheese, only appearance had significant variation (P<0.05) while other parameters had no significant variation (P>0.05). T1 had high values for appearance (4.15), smell (3.70), taste (3.65), texture (3.50) and acceptability (3.75). T4 had low values in appearance (3.55) smell (3.35), taste (3.20) and acceptability (3.20) well T2 had the lowest value in texture (3.20). The study demonstrates that the choice of coagulant used in cheese production affects both the nutritional attributes and sensory preference of consumers.

Vinegar (T1) and lemon juice (T3) are recommended for commercial cottage production due to the nutritional values and high yield percentage while for cream cheese vinegar (T1), lemon juice (T3) and unripe pawpaw pulp (T4) are recommended. Lime juice (T2) is recommended for small scale cottage cheese production or for personal consumption due to it’s high sensory acceptability while for cream cheese small scale production vinegar (T1) and lime juice (T2) are recommended