Key findings:

The study demonstrated that butter produced with skim camel milk cream and anhydrous milk fat, and inoculated with lactic acid bacteria, resulted in lower cholesterol and higher therapeutic qualities compared to the control. Treatment A2, aged for 24 hours, showed the best chemical, microbial, and sensory properties, including lower acid degree value, peroxide number, and cholesterol content, while maintaining higher viability of therapeutic bacteria throughout storage.

What is known and what is new?

It is known that traditional butter often has high cholesterol and may lack therapeutic qualities. This study introduces a novel approach using cream from skim camel milk and anhydrous milk fat, combined with lactic acid bacteria, to produce butter with significantly lower cholesterol and enhanced therapeutic benefits. The innovative process, especially in treatment A2, demonstrates improved chemical, microbial, and sensory properties, highlighting a new method for producing healthier butter.

What is the implication, and what should change now?

The findings suggest that incorporating lactic acid bacteria in butter production can significantly reduce cholesterol levels and improve therapeutic qualities. Producers should consider adopting this method to offer healthier butter options. Further research and development should focus on optimizing this process for commercial production to meet consumer demand for nutritious and beneficial dairy products.

Camel milk has unique benefits for human health. Proteins are the main component of camel milk, which gives it unique characteristics. Milk contains 9.7% essential amino acids, with a high content of immune proteins Magdi et.al; (2010) and Sabahelkheir (2012) [1,2], Milk is rich in vitamins C and B equivalent to three times what is found in cow's milk, magnesium zinc, iron and calcium twice as high It acts as antioxidants by removing the harmful effect of free radicals, preventing cancer and improving the nutritional value of milk. Magjeed (2005) and Afifi (2010) [3,4], Milk fat contains 2% homogeneous polyunsaturated fatty acids that give smooth texture and white appearance. Prajapati (2012) [5], Cholesterol is one of the important components of fat and it is considered one of the compounds that affect health if it exceeds a certain level in the blood as it causes heart disease and atherosclerosis As it is known, cholesterol is found on the cover of the fat granule in milk fat. From this point of view, Prajapati studies began to manufacture low-cholesterol butter by using some chemicals to remove cholesterol and obtain healthy butter, but because of the dangers caused by these substances, the trend was to use probiotics and lactic acid bacteria that are used In this regard, this is a note Kim et.al;(2006) and Kumar et.al; (2010,[6,7]  Therefore healthy microorganisms were used to try to reduce cholesterol due to the role played by these microorganisms as they are believed to work on consuming cholesterol and decomposing it Serajzadeh & Alemzadeh (2008),  [8]Because of the availability of anhydrous milk fat at reasonable prices especially from imported ones it is possible to produce butter from anhydrous milk fat and skim milk noting that anhydrous milk fat is less susceptible to rancidity Woo & Lindsay (1984) [9], The aim of this study was to use camel milk because of its health benefits with anhydrous milk fat available in the market and aged with therapeutic bacteria to manufacture healthy and low-cholesterol butter suitable for sick and healthy people and to improve its sensory and structural qualities.

The source of camel milk was obtained from the west of the city of Nineveh in the Rabia region from one of the breeders of a herd of camels of desert color, and the anhydrous milk fat was obtained from the Al-Jazeera Dairy Company in the city of Nineveh.

Use a mixture of lactic acid bacteria starter (lactobacillus.acidophilus + Bifidobacterium.bifidum) with an addition of 5%, which was obtained in lyophilized from the Danish company chr.Hansen.

These bacterial cultures were activated using dried sorted milk (skimmed) of the French Reglia brand after it was recovered with distilled water at a ratio of 12 gm milk per 100 gm distilled water and was autoclaved at 121°C for 15 minutes according to what was mentioned in Benson (2002) [10].

 The number of lactic acid bacteria was estimated using cast plates using Deman Rogosa Sharp (MRS) medium, and this was stated in Speak (1984) [11].

Butter preparation method:

Camel milk was sorted using a mechanical separator to obtain sorted milk. The proportion of the components was 91.7% moisture, 3.4% protein, 3.9% lactose and 0.76% ash. The cream was prepared by mixing sorted camel milk with anhydrous milk fat which contains 0.1% moisture and is heated at 60 degrees. Percentage with an addition ratio of 3:1 (volume / weight), The mixture was well mixed by means of an electric mixer in a water bath for 10 minutes. The percentage of fat in the cream was 35-40%. The cream was flash pasteurized at a temperature of 85 °C for 15 seconds, At this stage, the material was added. The emulsified lecithin at a rate of 0.3%, then cooled to room temperature and divided into three parts. The cream of the first part was left for self-fermentation at a temperature of 15 °C for a period of 24 hours It represents control treatment C And the second and third sections of the cream were added to it a mixture of lactic acid bacteria starter (lactobacillus.acidophilus + Bifidobacterium.bifidum) at the rate of adding 5% of the weight of the cream, then incubated at 15 degrees Celsius for 18 and 24 hours. This experiment represents treatment A1 and A2 respectively, and after Incubation The cream was shaken at a temperature of 12 degrees Celsius, and after the formation of the butter, it was separated from the buttermilk, then the butter was washed with water and 1.5% salt was added to it , The butter was placed in a sterile container and kept in the refrigerator at a temperature of (5 ± 1) C for a period of 6 weeks.

Chemical analyses

The chemical components of moisture, fat, and protein were estimated according to the method described in Joslyn (1970) [12], and the amount of ash was determined according to what was mentioned in A.O.A.C. (2005) [13], and the moiety acidity and pH were estimated according to what was mentioned in A.O.A.C. (2005) [13], and the acid degree value of the fat was measured as stated in A.P.H.A. (1978) [14], the peroxide number was estimated as stated in the method of A.O.A.C (2000) [15], cholesterol was determined by the method described in Sabir et.al; (2003), and the proportion of the amino acid tyrosine was measured by the method described in A.O. A.C. (2004) [16].

The numbers of total bacteria, Psychrophiles bacteria, coliform bacteria, yeasts and molds were estimated as mentioned in A.P.H.A. (1978) [14].

The sensory evaluation was estimated according to the form proposed by Nelson & Trout (1964), and the data were analyzed statistically according to what was mentioned by Al-Rawi and Khalaf Allah (1980) [17].

Table (1) The chemical composition of the butter treatments

The different letters in the above table indicate that there are significant differences at the level (P≤0.01).

Table (1) show that the percentage of fat in the control treatment C is within the standard limits for butter, which amounted to (80.40%) and this falls within the Joint FAO/WHO (2000) legislation, while the percentage of fat for butter treatments A1 and A2 was lower and amounted to (78.60 and 78.54%) respectively and the reason may be attributed to the action of lactic acid bacteria that consume fat, and it was noted that there were no significant differences in the proportion of protein between the treatments, with a slight increase in the mosture content of the butter treatments A1 and A2, and this is consistent with what was found by Kim et.al; (2006) [6], and it was noted A decrease in the pH value and an increase in the acidity of the butter treatments A1 and A2, compared to the control treatment, where the lowest pH and the highest acidity were in the treatment A2 and reached (5.30 and 0.35) respectively The reason may be attributed to the action of lactic acid bacteria on acid production, and this is consistent with what was found (Abbasy 1998) [18] increased the acidity of butter by using lactic acid bacteria.

Table (2) Acid degree value (meq / 100 g fat) for butter treatments stored at temperature (5 ± 1 ºC) for a period of six weeks

The different letters in the above table indicate that there are significant differences at the level (P≤0.05).

It was noted from Table (2) that there were significant differences in the value of ADV for all treatments and there was a rise with the advancement of the storage period in all treatments but at time zero, all values were universally acceptable within the gradient approved by the BDI method, which stipulates that the value of ADV should not exceed more than (2.00 meq \ 100 g fat) because the higher it is, the rancid flavor will be felt according to Deeth & Fitz_gerald (1976), where the ADV value at time zero was (0.95, 0.79 and 0.73 meq \ 100 g  fat) for treatments C, A1, and A2 respectively and with The storage period progressed for a period of 6 weeks. It was clear that the ADV value of the control butter was within the limits that were not permitted according to the BDI method and amounted to (2.13 meq / 100 g fat) The reason may be attributed to the shaking process, which may lead to fat decomposition, or to the presence of phospholipids in the butter that activate the lipase enzyme, or to the presence of a bacterial lipase enzyme that is not significantly affected by pasteurization. Jinjarak et.al; (2006) [19], while the ADV value of treatments A1, A2 after 6 weeks of storage were within the acceptable limits which amounted to (1.67 and 1.50 meq / 100 g fat) respectively The reason is attributed to the action of lactic acid bacteria that inhibit unwanted bacteria, as well as its ability To produce antioxidant compounds and prevent the formation of free radicals, and this is consistent with what was mentioned by Ihsan, et.al; ( 2002) [20].

Table (3) Peroxide number (meq/1kg butter) for butter treatments stored at temperature (5 ± 1 °C) for six weeks

The different letters in the above table indicate that there are significant differences at the level (P≤0.05).

 Table (3) that there are significant differences in the PV value for all treatments and there was a rise with the progression of the storage period in all treatments, but at time zero all values were acceptable as the PV value at time zero was (1.55, 1.00, and 0.95 meq /kg butter) For treatments C , A1 and A2 respectively which are within the permissible and legalized limits of the quality guide of the General Company for Dairy Products (2005) [21], and with the progression of the storage period it is clear that the PV value rises and the highest rise was in the control treatment in the sixth week which amounted to (3.64 meq / kg butter). The cause is attributed to oxidation due to moisture, polluting bacteria, or metals. Couverur et.al; (2006) [22], and after six weeks of storage, treatment A2 recorded the lowest height, followed by treatment A1, which amounted to (1.90 and 2.00 meq /kg butter) respectively. The reason is due to the action of lactic acid bacteria in their ability to produce antioxidant compounds and prevent the formation of free radicals, and this is consistent with what was mentioned by Ihsan, et.al; (2002) [23]. 

Table (4) Cholesterol concentration (mg/100g butter) in butter treatments stored at temperature (5 ± 1 °C) for six 

weeks

The different letters in the above table indicate that there are significant differences at the level (P≤0.05).

Table (4) that there is no significant difference at the level (P≤0.05) in cholesterol in the control treatment, but in the fifth and sixth week there was a slight decrease in cholesterol and it amounted to (210.00 mg / 100 g butter), and this is close to the result obtained by Hatice & Zübeyde (2006) [24], while a decrease occurred in the percentage of cholesterol since the first week in the rest of the treatments as the decrease continued with the progression of the storage period The reason is due to the ability of therapeutic bacteria to produce enzymes that break down fat or break down cholesterol to take advantage of it as a carbon source, which leads to lowering cholesterol. - Elsalam et.al; (2004) and Al-Rawi (2005) [25,17], and the lowest percentage of decrease occurred in the sixth week of storage and was in treatment A2 then treatment A1 and reached (43.00 and 55.00 mg / 100 g butter) respectively, and this is evidence of the possibility of introducing bacteria Therapeutic in the manufacture of healthy low-cholesterol butter.

Table (5) Tyrosine concentration (µg/1g butter) in butter treatments stored at temperature (5 ± 1 °C) for six weeks

The different letters in the above table indicate that there are significant differences at the level (P≤0.05).

Table (5) indicates that the amino acid tyrosine is considered as a measure of the degree of protein degradation, as it was noted that the highest percentage of tyrosine in butter immediately after manufacturing was in control treatment C, followed by treatment A1, then treatment A2, and it was (22, 10 and 8 μg / 1 g butter), respectively. The reason for the action of the additive therapeutic bacteria that works to limit the growth of proteolytic bacteria, especially cold-loving bacteria that are able to secrete protease enzymes that are resistant to the heat of sterilization is because natural milk proteases are inhibited by pasteurization, so the therapeutic bacteria works to inhibit the growth of cold-loving bacteria and the production of bacteriocins [26]. A rise in the proportion of tyrosine was noted for all treatments with the advancement of the storage period, and the highest increase was in the control treatment, which reached the sixth week of storage (95 μg / 1 g butter) The reason may be attributed to the action of proteolytic bacteria, which may withstand the heat treatment temperature Vasbinder et.al; (2003) [27], while it was followed by the increase in the percentage of treatment A1 and then treatment A2 after six weeks of storage and amounted to (25 and 17 μg / 1 g butter), respectively. The reason may be attributed to the action of lactic acid bacteria that inhibit unwanted bacteria and thus stop and reduce From proteolysis and help in prolonging the shelf life of butter.

Table (6) Number of lactic acid bacteria, total bacteria, Psychrophiles bacteria, coliform bacteria, yeasts and molds (cfu/g) in butter treatments stored at temperature (5 ± 1 ºC) for six weeks

The different letters in the above table indicate that there are significant differences at the level (P≤0.05).

Table (6) indicates the microbial content of butter, where we notice an increase in the number of lactic acid bacteria in the first and second week of storage, and it reached the highest number in treatment A2, followed by treatment A1, and it was (152 and 140 x 10⁶ cfu/g) respectively, but a decrease occurred in the number of therapeutic bacteria which started from the third week until the sixth week, but the viability of the therapeutic bacteria continued throughout the storage period, and treatment A2 contained the highest number of therapeutic bacteria, then followed by treatment A1 and after six weeks the therapeutic bacteria in treatments A1 and A2 reached (10 and 14 × 10⁶ cfu/g) respectively where in these numbers lactic acid bacteria can have a therapeutic role and the butter is healthy and the survival rate in treatment A2 was higher than treatment A1 for the length of storage period, As for the numbers of total bacteria, we note that there are significant differences, as the number of total bacteria was increased in the control treatment C, which reached in the sixth week (270 x 10² cfu / g) in contrast to the rest of the treatments in which the numbers of total bacteria decreased with the progress of storage, as it reached in the two butter treatments. A1 and A2 for the sixth week of storage (6 and 3 x 10² cfu/g) respectively. The reason is attributed to the action of therapeutic bacteria that work to inhibit unwanted bacteria through the secretion of substances that inhibit competitive bacteria such as the bacteriocins of Al-Khafaji et al. (1998b) [28], As for the numbers of Psychrophiles bacteria we note that there are significant differences, as they decreased with the progress of storage in the butter treatments A1 and A2, which reached for the sixth week (126 and 114 x 10² cfu / g) respectively compared to the control treatment C in which the numbers of Psychrophiles bacteria increased Which reached in the sixth week (380 x 10² cfu / gm) and the reason is attributed to the action of therapeutic bacteria that are characterized by their antagonism with Psychrophiles bacteria that work to prevent their growth Al-Khafaji et al. (1998a) [26], As for the numbers of coliform bacteria, yeasts and molds, the Iraqi standard specifications stipulate that the numbers of yeasts and molds do not exceed 100 cfu / gm of butter, while the number of coliform bacteria does not exceed 10 cfu / gm of butter, and we note that the butter treatments A1 and A2 were free of coliform bacteria As well as from yeasts and molds, except for treatment A1, which contained one cell of coliform bacteria at time zero, then it disappeared in the first week of storage. The reason is attributed to the action of lactic acid bacteria on inhibiting other organisms, as well as because of the acidity it produces, which makes the medium unsuitable for the growth of coliform bacteria, yeasts, and molds Robinson (1990) [29], while it was observed in the control treatment C, in which coliform bacteria exceeded the permissible limits until the third month to reach (11 cfu / g butter), as well as the number of Yeasts and mold sexceeded the permissible limits until the fourth month to reach (110 cfu / g butter), and this It indicates the possibility of producing therapeutic butter containing a live percentage of therapeutic bacteria even after six weeks of storage.

Table (7) Sensory evaluation in the parameters of butter treatments stored at a temperature (5 ± 1 ° C) for a period of six weeks

Table (7) shows the results of the sensory evaluation of the stored butter treatments, as treatment A2 obtained the best evaluation score for fresh butter immediately after manufacturingand reached to (95%) and was characterized by the same taste and smell of butter and was homogeneous in appearance and texture and free of impurities, then followed by the quality degree of treatment A1 while the control butter treatment got the lowest degree Evaluation It is believed that the reason is the use of lactic acid bacteria that limit microbial growth and reduce the degree of fat decomposition and limit the appearance of rancid flavor. A decrease was observed in the sensory evaluation scores for all treatments with the advancement of the storage period, especially in the butter of the control treatment, where a deterioration occurred in the sensory characteristics due to fatty decomposition And the increase in the peroxide number, which led to a deterioration in the texture and taste, and became unacceptable to the consumer, especially in the fifth and sixth weeks of storage, as the evaluation score in the sixth week of the control treatment reached (45%) While treatment A2 butter continued to maintain its sensory characteristics even after six months of storage, then treatment A1 butter followed, and the degree reached (70 and 64%) respectively, as they were within the acceptable limits according to the global gradient of the degree of fatty decomposition, and it was the best evaluation score in taste, flavor and color And the tissue along the storage period is in A2 treatment butter, and this confirms the possibility of using dry milk fat with camel milk and lactic acid bacteria to produce low-cholesterol therapeutic butter and within the international standard specifications, with the possibility of extending the butter preservation period for a longer period.

Conflict of Interest:

The authors declare that they have no conflict of interest.

Funding: No funding sources 

Ethical approval: The study was approved by the Institutional Ethics Committee of University of Mosul 

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