Evaluation of Paper and Cardboard Waste and Their Possible Applications in Producing Fuel Briquettes

Human (Breast) Milk

According to the World Health Organization (WHO), the best way to breastfeed is to start early, exclusively breastfeed for the first 6 months, feed frequently, breastfeed for two years, and increase breastfeeding during times of illness [17]. Early initiation of breastfeeding means starting to breastfeed within one hour of childbirth. This practice has many benefits, such as boosting the baby’s immune system, lowering diarrhea risk, and progress the overall child survival rates. At the first month of birth there were about 2.7 million newborns passed away in 2015 worldwide, with more than a third of these deaths occurring on the first day. This number of deaths could be minimized to 33% when mothers practice early initiation of breastfeeding [17, 18, 19, 20].

Several data had illustrated the impact of 12 months of lactation on obesity, blood pressure, type 2 diabetes with low risk of ovarian and breast cancers, decreases blood pressure and the rates of postpartum depression for mother. This practice had an impact on the sleep patterns of not only the children but also their mothers. It is important to highlight that breastfeeding through skin-to-skin contact can offer solace to both mothers and children in moments of tension or unease [21, 22, 23, 24, 25]. There are some diverse roles of breast milk proteins like aiding digestion, boosting the immune system, protecting against harmful bacteria, viruses, and yeasts, as well as supporting the growth and function of the gastrointestinal tract [26].

Globally, in 2022 it was assessed that the potential of breastfeeding saved 574 billion USD (0.7% of global Gross Domestic Product, GDP), and more than 10% of household’s wages by not having to purchase infant formula [27]. Colostrum that rich in immunoglobin G; is the first milk formed in the beginning days after birth that is very paramount for protecting against newborns infections. It prevents many of bacterial, viral, fungal and protozoa infection for the babies. Some researches explained that children who didn’t feed colostrum could suffered from various infections such as stunting, underweight, and wasting [17, 28, 29, 30]. In general, colostrum has high ratios of growth factors and immunologic components such as secretory immunoglobulin A (sIgA), lactoferrin, and leukocytes, and contains relatively low concentrations of lactose, lipids, and energy. So, it could be concluded that the substantial mission of colostrum is trophic and immunologic more than nutrition [30]. Hsu, et al. [31] indicated a shortage in secretory immunoglobulin levels, with a constant concentration in calcium, lactoferrin, and lysozyme based on the stage of lactation. Specifically, protein concentrations were noticeably elevated in extremely premature milk (less than 28 weeks) compared to moderately premature and full-term milk. In contrast to full- term milk, premature milk is distinguished by higher levels of immune proteins and lower levels of nutritive proteins [32]. However, breast milk protein which don’t have fractions like αs1-casein, αs2-casein and β-lg; has low level compared to a high ratio of protein in cow milk which contained β-CN as the major casein fractions as shown in Table 3, but contain a high content of lactoferrin (LF). The exceptional digestibility rate of approximately 95%, along with its superior amino acid profile, establishes milk protein as a top-tier protein source in terms of quality [33, 34], but contain a high content of lactoferrin (LF). It also owns high digestibility of ~ 95%, combined with a superior amino acid composition, makes milk protein a “high quality protein” [35].

Bovine (Cow) Milk

Bovine milk the copious milk which consumed for thousands of years had been recorded in ceramic pieces dating back 7500 years [36]. Nevertheless, many high- producing dairy cows have the ability to effectively manage lactational issues while maintaining good health [37]. Milk composition alters between breeds of cows, but generally includes protein (both casein and whey proteins), fat, lactose, alongside extolled minerals and vitamins. The cow’s milk protein is highly nutritious, as it is copious in essential amino acids such as leucine, isoleucine, valine, lysine, histidine, methionine, and phenylalanine. These amino acids contribute to various health functions and provide significant nutritional value [9].

Bovine proteins are assorting to 4 categories: caseins (including αS1-, αS2-, β- and k-caseins) and whey proteins, also renowned as serum proteins, which consist of different fractions as mentioned in table 4. Among these fractions, α-lactalbumin (α-La) acts as a component of lactose synthase and has antimicrobial and anticancer properties, while β-lactoglobulin (β-Lg) serves as an immunoglobulin carrier till colostrum formation. Bovine serum albumin (BSA) exhibits anticancer with immunomodulatory effects, and Lactoferrin (LF) is a glycoprotein with iron-binding capabilities similar to transferrin, along with antimicrobial, antiviral, immunomodulatory, antioxidant, and antitumor properties. Lysozyme also plays a role in antimicrobial defense, while immunoglobulins save the mammary gland from infections. Additionally, minor whey proteins such as proteose peptones (low molecular weight peptides derived from caseins), proteose peptone component3 (PP3), milk fat globule membrane (MFGM), and lacto-peroxidase exhibit antimicrobial and antioxidant properties Table 4 [9, 38].

There is nearly 30-35 g protein/L in ordinary bovine milk, the ratio of this protein is divided into 80% for casein micelles and 20% for whey proteins. Milk protein can precipitate by lowing pH to 4.6 at 20ᵒC or using chymosin enzyme into casein and whey proteins. It was recognized that there were 7 variants of αs1-CN, 4 of αs2-CN, 9 of β-CN and 6 of κ-casein. αs1-, αs2- and β-CN are called calcium sensitive fraction, whilst κ-casein is called “protective colloid” as it stabilizes casein micelles [33].

In the same vein, Brophy, et al. [39] expounded that four fractions of casein bovine milk which are αs1-, αs2-, β-, and κ-casein, aggregated into large colloidal micelles and also managed physicochemical properties of milk such as structure and stability.

Thus, improvement of milk characteristics could increase by growing casein concentration. As it known that κ-casein; which coats the surface of the micelles has a serious part in improving heat stability and enhancement the properties of cheese product. Further, good processing characteristics correlated with high content of β-case in which contain minimized rennet clotting time and boosted whey ejection.

As well as β-casein has two familiar variants (A1 and A2); A1 has His67 whilst A2 has Pro67. There had been known that many of biological effects can output from β-casein; the famous on is called casomorphin-7 between the position of 60 to 66 amino acid [40]. Compared to human, cow milk has less amount of α-la, lactoferrin, immunoglobulins and lysozyme as seen in previous Table 3.

Buffalo Milk

Buffalo (Bubalus bubalis) milk production is stated the second largest source after bovine milk in the world. Total universal milk production is around 13% (87.5million tones/ year), and also has high annual growth rates. It has high ratios of fat, protein, lactose, total solids and some minerals compared to cow, human, goat and camel milk [41].

One of the most countries that produces buffalo milk is Pakistan with 35.5 billion liters annual milk production (67.04%) followed by cow (31.56%) milk [42, 43].

Buffalo milk has all useful compounds, like peptides, fatty acids, vitamins, and other bioactive compounds. It characterized with elevated concentrations of total protein, medium chain fatty acids, CLA, vitamins A, D, C, B6, minerals (calcium, magnesium, phosphorus, potassium, zinc and iron) and contents of retinol and tocopherols than cow milk. Buffalo milk contains high ratios of immunoglobulins (Ig) which identified of (IgGa, IgA1, IgA2 and IgM) against cow and breast milk. Cow milk has lower content of lactoferrin than in buffalo milk, as displayed in Table 5 which compared both to human milk [44, 45].

Buffalo milk protein has ~80% caseins and ~20% whey proteins with traces of minor proteins, so BM is more preferred to consumer [46]. It possesses more colloidal calcium and phosphorus accompanied with high ratio of calcium than cow one. Contrast cow milk which contained 90- 95% of casein micelles; BM owns the casein in the micelles form. In addition, buffalo milk contains slightly higher ratios of β-lactoglobulin than cow milk, which is absent in human milk [41].

Also, same Table appeared that buffalo milk (BM) had higher content of α-s2-CN and κ-casein. The excessive amounts of κ-CN in BM can be believed that it acts as a laborer to accelerate the enzymatic phase of rennet coagulation and therefore it will be needed little quantity of chymosin in cheese manufacture [44].

There was great homology (97.2%) between αs1-CN of BM which contains a single 199 residue polypeptide chain compared to variant B of αs1-CN of bovine milk. Buffalo αs2-CN is considered of a single polypeptide chain with 207 residues in length and has very high homology (97.9%) compared with cow αs2-CN. Table 6 gave an outline of amino acid substitutions in both of buffalo and cow milk [47].

Goat Milk

As mentioned in a number of researches, about 500 breeds of goats live in the high mountains and deserts in the world which found more 95% of its population in developing countries [48]. India is the largest producers of goat milk in the world (26.3%) followed by Bangladesh (14.3%), and leaders among the European countries are France (3.8%) and Greece (3.3%). According to the rapid population growth, production of goat milk becomes a substantial issue to human nutrition in the tropical developing countries [49, 50]. United Nations explained that goat milk can be used as an important application to attain the 2030 Agenda for sustainable development goals [51]. Sharma, et al. [52] exhibited goat milk proteins which are composed of 80% casein the major protein and 20% whey protein; have remarkable variations in their compositions against milk of other mammalian species. They are a family of acidic, proline-rich phospho-proteins designed to form spherical, large, micelles structures in colloidal suspension with calcium phosphate. Moreover, the obvious differences between cow’s milk and goat’s milk in digestion is that the latter has a shorter clotting time, lower resistance to heat, weaker curd hardness and lower cheese yield what has been explained by the “homogeneity” of goat’s milk fat [53]. Feeding on goat milk; which contains about 1.2g calcium and 1 g phosphate/L furnishes a worthy ratio of them similar to those in cow milk. The soft curd and high buffering capacity of goat milk may be perfect for adult humans suffering from gastrointestinal disturbances and ulcers [50].

An important nutritional property of goat’s milk for infants, adults, or those with a cow’s milk allergy is that it has a high biological value digestive and physiological capacity [54]. Due to lower content of αs1-casein (5% of the total casein) in goat milk that makes it less susceptible to cause allergic reaction compared to cow milk and therefore decreases the sensitivity to the other allergen protein, which is β-lactoglobulin. As well, data declared that the best composition of exogenous amino acids can be found in goat and sheep milk. In general, goat milk compared to cow milk is less rich in lactose, fat and proteins, but has similar mineral content [49].

GM which its density ranges between 1.026 and 1.042; gained alkaline pH 6.3 to 6.7 verses to cow milk which is tend to acidity. It has a white-matte color, no β-carotene and a sweet and pleasant distinctive “freshly milked taste”; however, it can sometimes, at the end of lactation or after a period of storage in a cold environment, acquire a certain flavor one can describe as “animalic” [54]. The intense of goat milk flavor may be cause of the release of short-chain fatty acids during the handling of milk [50].

One of the key benefits of utilizing goats for milk production is their ability to thrive in challenging environmental conditions compared to cows. This makes goats a practical choice for milk production, especially during times of climate change that can negatively impact livestock. The unique qualities of goats make them a preferred option for milk production, particularly for vulnerable populations and those with financial constraints. The growing global acceptance of goat milk for human consumption is evident in the rapidly expanding goat milk market worldwide. Therefore, promoting research on goat milk production is crucial for enhancing food security and combating hunger on a global scale. Despite the lack of existing research on the importance of goat milk in enhancing food security, it is clear that further scholarly research on this topic is essential [55].

Goat milk has a higher concentration of non-protein nitrogen compounds compared to sheep and cow milk. Additionally, it contains fewer types of casein proteins. This unique composition results in a softer texture in goat milk yogurt, as opposed to sheep milk which has a stronger ability to coagulate. The differences in casein proteins in sheep milk are the primary reasons for its quicker curd formation and firmer rennet coagulation. Both goat and sheep milk also boast higher levels of essential minerals and vitamins compared to cow milk [54].

She-Camel Milk

Camel is an animal can be used for multi-purposes with high productions. In deserts camel can live and faces the problems like raise of global warming and scarcity of food and water. In 2018, the estimated global population was roughly 30 million, with the majority residing in Africa. Specifically, around 80% of the population calls Africa home, with 60% of that number concentrated in the Horn of Africa, notably in Somalia [62]. Four North East African countries Somalia, Sudan, Kenya and Ethiopia own about 60% of the dromedary camel population. Somalia has the largest herd in the world with over 6 million heads. Daily yields between 3 to 10 kg in a lactation period of 12 to 18 months are common [63]. Camel milk is drunk throughout Arabia, and it has low fat and high nutritious value. Lately, the European Union has also allowed import of camel milk from African and Asian countries into the EU [64].

Fresh camel milk has an ordinary odor, opaque white color, smooth texture due to homogenized milk fat and salty taste because camel is fond of grazing on salty vegetation. The chemical composition of camel milk compared to cow one is cleared in Table 9. Camel as cow milk has highly obvious protein compared to human milk but lower than buffalo milk. It has a similar low-fat content as human than buffalo and cow milk. Camel milk is similar to goat milk in protein and lactose contents. It has a comparable content of fat, moisture, total solids and carbohydrate with cow and goat milk. So, the composition of camel milk is closer to human milk and of high nutritional value and therapeutic effects [64, 65].

Lactose concentration is about 4.8%, but this sugar is easily metabolized by persons suffering from lactose intolerance. Camel milk also is suitable for allergic patients with absence of β-lg high amount of α-la and a different beta- casein. Camel milk is considered harmonious with human one due to it consists of a number of Igs. Camel milk dose not has β-LG makes it similar to human milk, so it is able to substitute human milk for infant diet formulation compared to cow milk. High level of whey proteins fractions in camel milk might supply great advantages of functional properties to camel milk consumers [66].

On the hand, this milk includes high ratios of Fe, Cu and chloride which make its salty taste. One of the most important features is long-shelf life; 3 days for raw milk, 10 days for pasteurized one. This property is naturally coming from its antibacterial system (lysozyme, lactoferrin and hydrogen peroxide) [67].

Even though camel whey proteins have higher heat stability than bovine whey proteins at temperatures between 63 and 90ᵒC, bovine milk coagulates much slower at higher temperatures. This could be related to the absence or very low levels of β-lg and k-casein in camel milk as milk is more resistant to heat when it is characterized by a molar β-lg to k-casein ratio close to 1 [44].

Equine (Mare) Milk

The global horse population exceeds 60 million, with a majority found in America and Asia. In Europe, horses are primarily concentrated in the eastern regions. In impoverished and developing nations, horses are commonly used as a means of transportation, whereas in developed countries they serve various purposes, including milk production, especially in Europe. Compared to cow milk, horse milk has lower levels of total solids, fat, and protein, but higher levels of lactose, making their composition more similar to that of human milk [68, 69]. Mongolia, Kazakhstan, Kyrgyzstan or Tajikistan; these four countries are known of consuming mare’s milk [70]. Although that the exact production amount of mare’s milk is not accurately known, there are about 30 million people all over the world are regularly consuming this type of milk. As well in Italy, Hungary, The Netherlands and Germany; it has gained more value due to its positive health impacts; almost 1 million kg of mare’s milk are produced in Europe [71].

So, mare’s milk casein is in a moderate level between human and bovine milk. The ratio of casein to whey proteins in horse is around 1.1:1, which more closely likes human milk [70]. Compared to cow milk; the stingy existence of k‐casein in mare milk is causing higher average size of the micelle and showing various mechanisms for micelle stability [72]; these factors with the low total casein content, are maybe caused the weak coagulation properties. Table 10 had illustrated a comparison between equine, bovine and human milk either colostrum or mature milk [73].

In the same line, Mare milk has major biological value than bovine milk. Content of threonine, valine, cystine, tyrosine, and lysine amino acids decreased, but both of glutamic acid and proline raised with time after delivery. There are little reports about equine milk protein variation, especially for the balance between casein and whey protein which considered the main cause of cow milk allergy [74, 75]. Affirmative impact of mare milk consumption on diseases like atopic dermatitis had been displayed. Many studies recommended mare milk as a suitable substitute for cow milk in cases of severe IgE-mediated cow milk allergy [76].

Although horse milk contains a high percentage of calcium compared to cow’s milk, horse milk is weak in the acid and enzymatic coagulation process. Many studies mentioned that horse casein doesn’t coagulate by calf chymosin at pH 6.6 or by various enzymes but some micellar flocculation not gel formation [69]. One study used Withania coagulans extracted from fruit had coagulated milk, but they did not report any details of the physical and chemical properties of the curd obtained [77].

Donkey (Jenny) Milk

Eight million heads which considered being the highest donkey population all over the world are in China; also, major populations are in Pakistan and Ethiopia. In the EU, there are around 288,000 donkeys, most of which live in Spain, France, Romania, and Italy. Jenny milk has been processed to meet nutritional requirements of definite people; this has improved income from donkey enterprises [62, 78].

Owing to its similarity to human milk, jenny milk is given an increasing attention, especially in Europe. Jenny milk has low contents of fat and cholesterol, even so it is considered most identical to human milk in protein and lactose contents. Human milk includes lower protein content compared to cow, buffalo, yak, camel, goat, sheep, and reindeer milk. Jenny milk, if modified appropriately, could be used as an alternative substitute in infant formulas to evade cow milk allergies [75, 79].

Inadequate information accrued about chemistry and nutritional properties of jenny milk contrast to mare milk. Obtainable results stated that jenny milk is nearly like mare milk with low total solids (8-10%) and protein (1.5- 1.8%) and high lactose (6-7%) and fat varies within 0.28- 1.82%. Likewise, its protein is low in casein (47.3%) and whey protein (36.9%), but it is rationally high in lactose and β-lactoglobulin (30%). The casein/ total protein ratio is once more similar to breast milk. It has Immunoglobulins (IgGs) in high content compared with human and bovine milk [75, 80].

Jenny milk owns high level in valine and lysine comparing cow, buffalo, goat, ewe, camel, and mare milk. It also included greater serine (6.2% vs. 4.8% and 5.1%), glutamic acid (22.8% vs. 23% and 17.8%), arginine (4.6% vs. 3.3% and 4%), and valine (6.5% vs. 4.8% and 6%) and lower cystine (0.4% vs. 0.6% and 1.7%) than cow and human milks, respectively. Its protein mostly contains αS1- and β-caseins, lysozyme, α-lactalbumin, β-lactoglobulin. β-lactoglobulin and α-lactalbumin contents were in average of 3.75 and 1.8 mg/ ml, respectively. Overall, jenny milk is characterized by low casein and high lysozyme content (1.0 mg/ml), compared with other milk [78, 81].

Although the characteristics of donkey milk are similar to those of breast milk, the expansion of its production on a commercial scale is uncertain. With all these special properties of donkey milk and some economic possibilities it can support children’s food [81].

Yak Milk

Yak milk is predominantly produced in the Qinghai-Tibet region of China, where yaks thrive in the challenging cold and high-altitude environments. China boasts a yak population of approximately 13 million, representing over 90% of the global yak population. The global production volume of yak milk is not officially documented, with estimates varying significantly from 0.7 to 40 million tons, as noted by Zhang, et al, [82]. Compared to cow milk, yak milk contains higher levels of dry matter, fat, and protein. The casein profile is similar, with slight variations in the concentrations of β and κ fractions. Notably, the casein micelle in yak milk is more hydrated and contains more colloidal calcium phosphate. While the average size of the micelle and fat globules in yak milk is slightly larger than in cow milk, as highlighted by Faccia, et al. [69].

The unique composition of yak milk lends itself to easy coagulation using rennet, a characteristic not commonly found in other types of milk. Bovine chymosin can effectively hydrolyze k-casein in yak milk, although the gel formation process is slower compared to cow milk. The firmer gel structure of yak milk is attributed to its elevated levels of colloidal calcium phosphate, facilitating the linking of casein micelles in multiple directions. Additionally, the larger size and higher hydration of yak micelles contribute to reduced curd syneresis and enhanced moisture retention. Yak milk’s coagulation properties are particularly advantageous for producing hard cheese in comparison to Holstein milk, owing to its higher concentrations of casein and calcium. By incorporating lactic acid bacteria starter, rennet, and CaCl2, high-quality hard cheese can be successfully crafted from yak milk, as detailed in the study by Faccia, et al. [69].

Fermented Dairy Products

The development of fermented dairy products using a combination of milk species, such as goat and camel with cow milk, has led to improved quality and the introduction of new products to the market. Yogurt, as noted by Aryana, et al. [86], is a widely consumed fermented dairy product globally, with annual production increasing significantly over the years. In 2015, yogurt production reached £4742.1 million, a substantial increase from £982.6 million in 1990. Despite the biological benefits and similarities to breast milk, donkey milk remains relatively underutilized in the dairy market. However, a study by Chivari, et al. [87] successfully demonstrated the production of a fermented beverage using donkey milk and probiotic bacteria like Lactobacillus rhamnosus and Lactobacillus casei. This study showcased the potential of incorporating jenny milk into fermented beverages enriched with probiotics, featuring a high lysozyme content and appealing taste profile.

Furthermore, research by Wang, et al. [88] highlighted that donkey milk possesses lower allergenic properties compared to cow milk and is rich in essential amino acids and polyunsaturated fatty acids (PUFAs) such as a-linolenic acid and linoleic acid. These findings underscore the nutritional value and potential health benefits of donkey milk as a viable alternative in the dairy industry.

The research findings suggest that utilizing sheep’s milk to create set yogurt with varying fat concentrations can yield superior quality and enhanced flavor. Specifically, sheep yogurt with low fat content, derived from 6.6% milk fat, demonstrated improved quality and reduced syneresis compared to yogurt with higher fat content. Furthermore, as the fat ratio decreased, the firmness of the curd also decreased, as indicated by Kaminarides, et al. [89]. This information underscores the potential benefits of producing sheep yogurt with lower fat content for optimal quality and texture.

The research study on yogurt production using sheep, camel, and goat milk highlighted the unique characteristics of camel milk that necessitate a longer incubation time of 16-18 hours compared to the 3-4 hours required for sheep and goat milk. This extended coagulation time in camel milk can be attributed to several factors, including the larger size of casein micelles, which results in a less efficient aggregation process and weaker gel formation, leading to a softer coagulum. Additionally, the antibacterial properties present in camel milk may interfere with the activity of lactic acid bacteria crucial for fermentation. Furthermore, camel milk exhibits lower levels of K-casein and total solids in comparison to sheep and goat milk [90]. In a similar study by Galeboea, et al. [91], it was found that when camel yogurt was enhanced with calcium chloride, gelatin, and skim milk powder, it exhibited comparable chemical and microbiological characteristics to cow yogurt. However, cow yogurt was preferred in terms of sensory properties. The addition of exopolysaccharides was also noted to improve yogurt texture more effectively than other additives [92].

The study made by Khalifa, et al. [93] on the production of set yogurt using various milk sources, including buffalo, camel, goat, and their combinations in different ratios, yielded significant findings. Camel milk was observed to contribute to a more liquid-like structure, while goat milk resulted in a mildly firm texture in comparison to the firm curd produced by buffalo milk. Blending buffalo milk with camel and goat milk in ratios of 50:50, 60:40, and 90:10 was found to enhance the characteristics of the curd, prolong its shelf life, and boost consumer acceptance. This research highlights the potential benefits of utilizing different milk sources and their combinations in yogurt production to improve product quality and consumer satisfaction.

The incorporation of mixed goat and cow milk in yogurt production has been shown to offer various benefits. Studies by Temerbayeva, et al. [94] demonstrated that blending goat and cow milk resulted in a yogurt product with higher levels of vitamins and protein, while reducing fat content. Additionally, the sensory attributes of the yogurt improved when combining goat and cow milk compared to using goat milk alone, with a ratio of 70% goat milk and 30% cow milk. Similarly, research conducted by Trentin, et al. [95] on yogurt produced from sheep and bovine milk, as well as their combinations, revealed that sheep milk contributed to a better nutritional profile in the final product. These findings suggest that incorporating different milk sources in yogurt production can enhance nutritional value and sensory qualities, highlighting the potential for innovation in dairy product development.

Kumis, a traditional drink made from mare’s milk, is renowned in various Asian countries for its perceived medicinal properties. It is believed to offer benefits to the nervous and immune systems, as well as aid in the treatment of conditions affecting the cardiovascular, respiratory, gastrointestinal, and urinary systems. This is attributed to its rich composition of enzymes, trace elements, antibiotics, and a diverse array of vitamins such as A, B1, B2, B12, D, E, and C. Research suggests that kumis can be beneficial for individuals recovering from certain illnesses and for pregnant women, as recommended by Jastrzebska, et al. [96]. It is important to consider these potential health benefits when incorporating kumis into dietary practices.

Cheese Product

The utilization of camel milk for cheese-making present’s challenges due to lower cheese yield and inferior product quality compared to traditional dairy sources. However, various efforts have been made to overcome these obstacles and produce different types of camel milk cheeses. One strategy involves using camel gastric enzymes instead of chymosin for cheese processing. Research studies have indicated that camel-derived chymosin exhibits superior clotting activity and κ-casein cleavage potential in comparison to chymosin sourced from other animals [97, 98]. This highlights the potential for utilizing camel gastric enzymes to enhance the cheese-making process and improve the quality of camel milk cheeses.

The research conducted by Khan, et al. [99] highlights the successful creation of soft white cheese from camel’s milk through a modified approach. By lowering the pH to 5.5 using citric acid or starter cultures and incorporating calcium chloride before rennet, they were able to produce cheese from camel milk. Despite a lower yield compared to cow or buffalo milk, the cheese made with starter cultures was preferred over acidification. This suggests that traditional cheese-making methods may not be optimal for camel milk and that alternative techniques are necessary for successful incorporation of camel milk into cheese production.

The study by Konuspayeva, et al. [100] highlights key factors influencing the use of camel milk in cheese production. The lactation period significantly impacts curd formation, with initial 12 days post-delivery showing no curd formation, followed by a soft coagulation phase starting after 24 days, suitable for cheese production. Optimal coagulation temperature was identified at 36ᵒC with a lower pH of 5.78, contrasting with 20ᵒC and a higher pH of 6.26. The introduction of a new coagulant, “Chy-Max M,” derived from Hansen™ (Denmark) containing camel chymosine, demonstrated effectiveness in cheese production. Various additives have been explored to enhance the quantity and quality of camel milk cheese. For example, the addition of calcium chloride during cheese manufacturing has shown to reduce coagulation time, improve cheese yield, and maintain organoleptic quality. Substituting camel rennet for bovine rennet has shown enhanced coagulation effects and reduced coagulation time, potentially due to the presence of pepsin enzyme in the rennet preparation. Incorporating yogurt culture or other lactic acid bacteria (LAB) with rennet in camel milk has accelerated coagulation by increasing lactic acid content, leading to improved texture and firmness of the curd. However, the addition of LAB or yogurt culture alone without rennet did not yield significant improvements in coagulation efficiency, as noted by Arain, et al. [98].

The challenges in cheese production from jenny milk, similar to camel milk, are attributed to its high whey protein and lysozyme content. A study by Iannella [101] utilized pure camel chymosin and starter cultures to create donkey cheese, yielding lower results compared to cow cheese, but with potential for improvement in the future. Goat cheese is widely produced globally, particularly in Mediterranean regions such as Turkey, Greece, Syria, and Iran. Initially focused on soft cheese, the production has evolved to include hard and ripened varieties. Factors influencing the sensory properties of goat milk-based products include genetic heredity of the animal, environmental conditions, and processing technologies [54]. Table 11 provides an overview of the potential applications of various milk species in different dairy products, highlighting the diversity and possibilities within the dairy industry.

The study conducted by Saadi, et al. [102] focused on the production of soft cheese using camel milk and aimed to address production challenges. They experimented with soft cheese formulations using camel milk, sheep milk, and various combinations of both. The data analysis indicated significant variations in total solids, fat, and protein content among camel soft cheese, sheep soft cheese, and their blends.

Notably, camel cheese exhibited the highest total solids content, while the cheese produced from a 50:50 ratio of the two milk types showed the lowest concentration. It was observed that camel milk experienced a notable loss of proteins, leading to reduced total solids content during storage. In contrast, sheep milk demonstrated an increase in total solids and cheese yield over the storage period. These findings underscore the importance of understanding the compositional differences between camel and sheep milk in soft cheese production and highlight the potential impact on product quality and stability during storage. Further research and optimization of processing techniques may be necessary to address protein loss issues associated with camel milk and enhance the overall quality of soft cheese formulations.