Cheese making and maturation are processes involving a multitude of complex biochemical events, mainly directed by the lactic acid bacteria that make up the ferment
One of the most important challenges of the dairy industry is therefore to choose the genera, species and bacterial strains best suited to the functions imparted to them in the various technologies for processing milk by fermentation
Consumers appreciate artisanal cheeses for their typical aromas and flavors, which are generally attributed to the metabolic activity of indigenous microflora present in raw milk. Various authors have observed that the use of pasteurized milk with indigenous lactic ferments helps to obtain cheeses with similar characteristics to products made with raw milk
Gouda cheese originated in Holland and was exported as early as 1600
The study presented here is part of a general approach, where we have therefore tried, on the one hand, to manufacture gouda-type cheese based on pasteurized cow's milk with different ferments and to establish the links between autochthonous strains, on the other hand, to clarify the influence of leaven on the physicochemical and sensory characteristics of manufactured Gouda.
The pasteurized cow's milk was supplied by the Aribs Dairy, Ain defla, Algeria, under appropriate hygienic conditions. Before its use, the milk was subjected to a set of physicochemical analysis to evaluate its hygienic and nutritional quality according to Amariglio
The eight strains used in this study, which were isolated from cow and goat milk from local Algerian populations in the region of KhemisMiliana, Ain defla and showed good technological functionalities
They are stored at -18°C in skimmed milk with 30% glycerol added. They are activated and maintained by a weekly transplanting on skimmed milk reconstituted at 10%
The starters were prepared in sterile skim milk, seeded with young cultures of the pure strains at a rate of 2%, and then incubated at 30°C for 16 hours. The ferments were chosen as follows:
The cheese was made at the ARIBS dairy, Ain Defla. We followed the manufacturing steps of Gouda as described by Goudédranche et al.
The manufacturing and maturation operations, identical for all the tests, were carried out three times for each ferment.
The first three ferments constituted by the autochthonous bacteria (F1, F2, F3) were evaluated for their acidifying potential at 30°C for 24 hours, according to the method of Larpent
The pH (expressed in pH units), and the acidity (°D) of local ferments are determined according to the method of AOAC
Cheese samples are taken at three stages of production: after 24 hours, 6 weeks and 12 weeks.
- The dry extract (DE; expressed in g per 100 g of cheese; %) is determined according to the method of AOAC
- The fat content (fat expressed in g per 100 g of cheese; %) is measured by the acid-butyrometric method of VAN GULIK
- The dosage of chlorides is determined by titration using a solution of silver nitrate based on the amount of precipitated silver chloride
- The ash content is determined according to the method described by the AOAC
- The determination of nitrogenous matter is carried out according to the Kjeldahl method
The cheeses were tested in triplicate by a panel of ten evaluators. A rating scale from 0 to 5 was used. The cheeses were rated on taste and paste criteria. When moving from one sample to another, the evaluators rinsed their mouths with water to erase the taste of the previous sample
The interpretation of the results obtained for the physicochemical and hedonic analyzes of the formulated cheeses is based on a statistical analysis using the statistical software XL-STAT Version 2014.5.03 (https://www.xlstat.com). The statistical analysis consists of a Multivariate Analysis of Variance with one factor (MANOVA) at the 5% level, a correlation using the Pearson correlation coefficient to detect a link between the various physicochemical parameters studied at the 5% threshold and finally, a Principal Component Analysis (PCA) at the 5% threshold.
The results found reveal that the three ferments F1, F2 and F3 have very important acidifying activities which results in the production of lactic acid during the 24 hours of incubation whose values reach 61 ± 0.04°D, 75 ± 0.31°D and 85 ± 0.02°D respectively [
Time |
F1 |
F2 |
F3 |
|
6 (hours) |
|
43±0.09 |
50±0.15 |
55±0.12 |
|
5.33±0.32 |
5.21±0.05 |
5.1±0.02 |
|
24 (hours) |
|
61±0.04 |
75±0.31 |
85±0.02 |
|
4.64±0.20 |
4.5±0.12 |
4.35±0.05 |
Means± standard deviation (SD) of three separate determinations
The prepared cheeses are cylindrical in shape, flat, 12 cm in diameter and 4.5 ± 0.10 cm thick, with convex sides and a net weight of 520 ± 25g [
The distribution of holes is reasonably even throughout the interior of the cheese, but with the acceptable presence of some openings and cracks. The shape is flattened cylindrical with convex sides. According to Huc
Cheese composition has also been identified in the literature as an important influencing parameter on the rheology of cheeses
The functional properties of cheeses are controlled by the chemical composition, including the moisture content. After 24 H, the average dry matter values recorded were of the order of 50.56±1.39%, 52.07±0.47%, 50.38±0.4% and 53.45±1.01% for the four cheeses manufactured respectively, these values increase after 6 weeks of ripening to reach 58.93±1.77%, 58.03±0.39%, 59.08±0.67% and 58.85±0.86% respectively. After 12 weeks, a loss of water was recorded and the dry matter values reached 70 ± 0.57%, 67.77 ± 0.46%, 65.12 ± 0.13% and 67.34 ± 0.65% respectively [
Time |
Parameter |
F1 |
F2 |
F3 |
F4 |
24h |
|
51.45±2.10 50.56±1.39 |
47.05±1.26 52.07±0.47 |
53.59±2.25 50.38±0.4 |
54.58±1.05 53.45±1.07 |
6 weeks |
|
40.16±0.67 58.93±1.77 |
38.17±0.65 58.03±0.39 |
37.79±1.03 59.08±0.67 |
41.04±2.17 58.85±0.86 |
12 weeks |
|
29.67±1.24 70±0.57 1.28±0.03 1.64±0.01 22.73±0.34 3.33±0.57 3.16±0.28 3.66±0.28 3.5±0.5 3.5±0.5 |
28.28±1.21 67.77±0.46 1.51±0.02 1.32±0.04 21.75±0.93 3.66±0.57 2.83±0.76 3.5±0.5 3.16±0.57 3.16±0.57 |
30.71±0.8 65.12±0.13 1.6±0.02 2.45±0.10 25.47±0.53 3.66±0.28 3.33±0.76 3.66±0.28 3.16±0.28 3.33±0.57 |
32.41±1.57 67.34±0.65 1.72±0.03 2.55±0.04 26.95±0.06 3.66±0.28 3.33±0.28 3.5±0.35 3.83±0.28 3.83±0.28 |
F1, F2, F3, F4: average of the 3 trials of cheeses made respectively with the ferments F1, F2, F3 and F4; DE: dry extract (%); FAT: fat (%); Ash (%); Protein (%); Texture, Flavor, Color, Odor, Aroma (note/5)
Chloride levels are significantly different (p≤0.05) in the four cheeses. It is higher in cheeses F3 and F4 (1.6 ± 0.02 and 1.72 ± 0.03%) than those of F1 and F2 (1.28 ± 0.03 and 1.51 ± 0.02%). Salazar et al.
We also found that the ash content in processed cheeses is significantly different (p≤0.05) and estimated at 1.64 ± 0.01%, 1.32 ± 0.04%, 2.45 ± 0.10% and 2.55 ± 0.04% for F1, F2, F3, and F4 respectively. Ashes are mainly composed of minerals from dairy raw materials; we find calcium, phosphorus, potassium, chlorine, sodium, magnesium, and table salt. Varunsatian et al.
Experimental values show significant protein levels in the finished product: 22.73±0.34%, 21.75±0.93%, 25.47±0.53% and 26.95±0.06% for F1, F2, F3 and F4 respectively. The analysis of variance reveals the existence of a significant difference (p≤0.05) between the different cheeses manufactured. According to Felfoul et al.
In the cheese industry, cheese quality is largely determined by sensory perception, which is a complex process. It is influenced by several factors such as the content of aromatic compounds, texture, and appearance
Gunasekaran and Mehmet
Several studies investigating the incorporation of lactic acid bacteria in spun pastes have reported a higher level of sensory perception of bitterness compared with conventional cheeses
The correlation test between the different physico-chemical and sensory parameters was studied. A Principal Component Analysis (PCA) is performed considering the different physicochemical and sensory parameters studied and the cheeses in question. The PCA shows that 82.63% of the total variance is represented on axes 1 and 2, with 52.35% for axis 1 and 30.28% for axis 2
The first PCA square characterizes the variables studied [Figure 3], so a negative correlation was noted for Dry matter, Chlorides, proteins, Ash, Texture and Flavor as well as for Texture, Odor, Color and Aroma. Two main positive correlations have been noticed; the first one gathers Fat, Odor, Aroma, Flavor, Ash, and Proteins, the second one gathers Proteins, Aroma and Flavor. Other positive correlations were also noted; Odor and Aroma, Ash, Aroma, Texture, odor and Flavor. Also note the presence of weak significant positive correlations: between Ash and Color, Chlorides, Flavor, Odor and Aroma, Dry matter and Fat, Fat and Chlorides).
On the PCA square characterizing the observations
• F4 cheese distinguishes itself from other cheeses by its aroma, Odor and Flavor, but also by its high fat content;
• F3 cheese is characterized by its high content of Proteins, Ash, and chlorides, and the better texture compared to other cheeses;
• F1 cheese is characterized by a considerable Dry matter content and preferred Color;
• The F2 cheese is very different from the F4 cheese; poor in terms of nutrition (it contains the lowest levels of protein, fat, and ash than the other tests), and the least appreciated during sensory analysis.
We have succeeded in making a semi-hard "gouda" type cheese from non-standardized heat-treated cow's milk, with ferments of appreciable organoleptic qualities and a satisfactory nutritional quality. All the indigenous strains used have good functional properties and can be promising cultures on the industrial level. After 12 weeks of ripening, we recorded a humidity of 31% and a fat content on dry matter of 30% on average. On the other hand, the prepared "Gouda" type cheeses have a very high protein content of 24.77±0.43, which gives them a high nutritional value.