Cottage Cheese Products from Concentrated Raw Materials
Head of the Scientific Information’ Analyses Department, Altai State Technical University, Russia
Received: December 15, 2016 | Published: January 16, 2017
Olga Musina, Head of the Scientific Information’ Analyses Department
Siberian Research Institute of Cheese-Making, Institute for Biotechnology, Food and Chemical Engineering at Altai State Technical University, Russia, Email:
Musina O (2017) Cottage Cheese Products from Concentrated Raw Materials. J Nutr Health Food Eng 6(1): 00185. DOI:
In Russia dairy products consume on daily basis. For it production we need complex of equipment for carrying out technological processes. Thus we studied the possibility of using existing equipment to produce cottage cheese and cheese products from concentrated raw materials, and the proposed technological line, which can be used at the enterprises of the dairy industry.
In addition to the cottage cheese on this technological line can be manufactured cheese products, curd desserts, curd paste, curd, dairy desserts and other concentrated dairy products by varying the ratios of the compounding components and the degree of evaporation of the milk mixture.
Technological lines of dairy products are widespread, mainly for cheese making. Such technological lines include milk acceptance and preparation area, a cottage cheese tub, means for separating whey, chiller and mixer with a device for supplying the filler. Such lines allow produce high-quality concentrated milk products, mainly cheese. But we lost part of components (dry solids) of raw milk: whey have significant amount of protein and fat, a significant part of the milk sugar and salts. Also the products obtained do not have varied organoleptic characteristics.
A large number of technological lines for cheese products with various fillers exist. For example, in Russian patent No. 43121 technological line of dairy products, mainly cheese, described. The line include milk acceptance and preparation area, a cottage cheese tub, means for separating whey, cooler, mixer equipment for preparing, chopping and serving filler, provided with a device for drying of the filler. This allows adding in concentrated dairy products a wide range of fillers, in particular, fillers requiring preliminary grinding and/or drying, and obtaining dairy products with varied organoleptic characteristics.
Nevertheless such lines contains a means for whey separation and presupposes the existence of the technological process of whey separation, and hence the loss of raw milk components along with the whey. Thus final product significantly reduces chemical value, potentially presented in raw materials. In addition, the separation of the whey is laborious and time-consuming operation.
The author set as objective the creation of technological line for cottage cheese products which would full use of raw milk dry matter, while getting the finished products with a wide range of organoleptic properties, as well as to minimize the whey separating process.
To solve this problem technological line for cottage cheese supplied vacuum-evaporating apparatus associated with a cottage cheese tub.
The supplying of the technological line with vacuum-evaporating apparatus enables to thicken raw milk and evaporate significant portion of the water to provide the necessary concentration of dry substances. Adjusting the degree of evaporation is possible for a wide range of concentrated products from raw milk: condensed beverages, cheese products, intermediate between the consistency, dairy spreads, cheese products, etc. It is important that by evaporation the concentration of raw milk increases, and amount of whey reduces (to zero depending on the type of final product), i.e. the components of raw milk used better, its dry solids are almost completely remain in the final product. Furthermore, the use of concentrated milk can significantly reduce the duration of the process of separating the whey by reducing its amount, until it is not necessary to separate the whey, depending on the final product.
Technological line for cottage cheese products from concentrated raw materials is schematically depicted in Figure 1.
Figure 1: Technological line for cottage cheese products from concentrated raw materials.
The line includes the milk acceptance and preparation area (not shown), consisting of the traditionally used units: the milk container, pump, separator-milk cleaner; a vacuum-evaporating apparatus 1; a cottage cheese tub 2; a means to separate the whey 3; a cooler 4; a mixer 5 with a device for supplying the filler 6; a chopper 7 and device for drying of the filler 8. All units are connected by piping 9 with shut-off and control valves (not shown).
As the vacuum-evaporating apparatus 1 can be used device, allowing to thicken raw milk in the shortest time at a temperature of 50-550 Celsius, increasing it at the end of condensation up to 55-60°C, for example a vacuum apparatus with the heating surface in the form of a tubular or plate heat exchanger.
The technological line for cottage cheese products works as follows.
Raw milk comes to acceptance and preparation area (not shown), where it undergoes processing in accordance with one of the known technologies. Then prepared raw milk enters into the vacuum-evaporating apparatus 1, where it is thickened to the desired concentration of solids. Further condensed raw milk arrives in the cheese tub 2. There we add the starter, milk-clotting enzyme, calcium chloride and/or other components for fermentation. Raw milk is mixed and leaved for fermentation. To obtain a more concentrated milk product by fermentation, a curd is pumped through the pipeline 9 into a means for separation of whey 3, where additionally separate the whey. The whey is withdrawn for reservation and a cottage cheese curd fed in a cooler 4.
It is possible to obtain concentrated dairy products that do not require whey separating, which is produced by the greater evaporation of raw milk. In this case after the vacuum-evaporating apparatus all raw milk fermenting forming a whole protein-carbohydrate-fat matrix.
From the cooler 4 concentrated dairy product is fed to a mixer 5 with a device for supplying the filler 6. The filler, if necessary, enters the device for drying 8, and passing the chopper 7 as fine particles also enters the mixer 5 with a device for supplying the filler 6. All components are mixed until a homogeneous mixture and are directed to filling and packaging.
Thus, supplying the line with the vacuum-evaporating apparatus gives chance to save the components of raw milk in cheese products, and to give them a different organoleptic properties, and also significantly reduce the amount and duration of the process of separation of the whey by reducing its quantity.
HSD: High Sucrose Diet, SBD: Starch Based Diet, WNIN/Gr-Ob: Wistar National Institute of Nutrition Obese rats, HOMA IR: Homeostatic model assessment Insulin Resistance, AUC: Area Under Curve, OGTT: Oral Glucose Tolerance Test, ROS: Reactive Oxygen Species.
Ageing is a universal phenomenon, defined as the process of gradual and spontaneous change, resulting in maturation through childhood, puberty, young adulthood and then decline through middle and late age. It is also the accumulation of various changes in physical, psychological, and social behavior of a person. The ever changing urbanization and life style is demanding more work, leading to stress and changed eating habits of people around the world. India is not an exception. According to WHO estimates, more than 1·3 billion adults worldwide are overweight, and a further 600 million are obese . Obesity is the major cause of disability and premature deaths in developing countries. Insulin resistance is the major etiological factor for diabetes and the risk association between obesity and diabetes is mediated through insulin resistance . Indeed, insulin resistance and visceral fat accumulation are two important culprits in the pathogenesis of metabolic disease and they predispose organisms to premature ageing .
India is ranked the highest in the world for obesity induced diabetes. It is estimated by International diabetes federation that the number of people in India with diabetes is 3.9% of total population and this may rise to 5.3% by 2030. This condition is partly due to genetic factors, specially the Asian Indian phenotype with the underlying biochemical abnormalities and partly due to dietary patterns and life style habits  with an increased number of young people succumbing to diabetes. The alarming rise in the number of people with type –II diabetes necessitates urgent attention as many of them show pre-aging or advanced or accelerated aging symptoms even at the age of 35-40 years. Accelerated aging is a faster-than-normal deterioration in the functioning of the body and mind. It is fast becoming an epidemic in developed and developing countries.
Obesity is the epidemic of the 21st century. In developing countries, not only is the prevalence of obesity continues to rise, but also obesity is occurring at younger ages. The World Health Organization estimates that globally there are >1 billion overweight adults [body mass index (BMI; in kg/m2) > 27], 300 million of whom are obese (BMI > 30) .Obesity per se accelerates the ageing of liver , thymus . Ahima et al.  reported that obesity accelerates the ageing of adipose tissue and in turn stated that this could be the connecting link between obesity, ageing and Type 2 Diabetes. Further, obesity is associated with increased brain age . In addition, Type 2 Diabetes per se accelerates ageing both in humans and rodents [8-11]. Concomitantly Dietary habits and diet composition is a crucial player in pathophysiology of T2D . Consumption of high sucrose diet leads to the development of obesity, insulin resistance, Type 2 Diabetes both in rodents and humans [13, 14]. Moreover, intake of high energy nutrients like sugars and fatty acids interact directly with genomic expressions, termed as nutrigenomics, ultimately leading to the metabolic syndrome .
It is clear from the above literature, that obesity and Diabetes per se can lead to ageing, but it is not clear whether superimposing Diabetes on obesity accelerates ageing and if yes the possible, underlying mechanisms. To understand the adverse effects caused by superimposing diabetes on obesity, WNIN/GR-Ob rats were used as the rodent models for obesity. These mutant rats were developed from the parental WNIN inbred rat strain maintained at the NCLAS, NIN, Hyderabad. WNIN/GR-Ob mutants are hyper-cholesterolemic, hyper-triglyceridemic and show obesity at 35 days of age. They are normoglycemic under fasting condition; are hyper-glycaemic when challenged with glucose orally  and they exhibit impaired glucose tolerance. Considering the exceptional feature that WNIN/GR-Ob rats obese and glucose intolerant, we considered it appropriate to induce Type 2 Diabetes in these rats by feeding High Sucrose Diet (HSD) for a period of 6 months. Studies were carried out in different tissues (brain, liver) at two different time points (3 and 6months) of feeding, to correlate aging with diabetes and obesity as compared to their corresponding age and sex matched counterparts fed Starch Based Diet (SBD).
Results and Discussion
Ageing is an inevitable and universal biological phenomenon. It occurs at its own rate, by passing through several stages of life. Healthy Life span is influenced by several environmental factors, genetic predisposition, lifestyle related changes etc.. Longevity is reduced by the progressive accumulation of macromolecular damage. Increased macromolecular damage is the strongest causative factor of ageing. In the present study the damage to macromolecules was studied in brain and liver. To the best of our knowledge this is the first study linking diet, diabetes, obesity and reduced longevity.
Survival analysis to determine the longevity of HSD fed WNIN/Gr-Ob rats
The effect if any of the HSD feeding on the longevity of rats was evaluated by Kaplan Meier survival plots and cumulative hazard plots . It was interesting that the survival of rats fed HSD was lower than those fed SBD indicating their reduced longevity. In line with reduced longevity, HSD fed rats had higher levels of cumulative hazards than SBD rats suggesting that the decreased longevity / survival of the HSD fed rats could be due to higher cumulative hazard in them.
Biochemical parameters to assess induction of Diabetes
Pre-diabetic state is a pathological condition characterized by aggravated insulin resistance . Insulin resistance is assessed by computing HOMA IR using the fasting plasma glucose and insulin levels, in addition to determining insulin AUC during the OGTT. We observed that HSD fed rats had significantly higher fasting plasma insulin, HOMA IR and insulin AUC during the OGTT compared to their SBD counterparts, at both time points of feeding studied. However plasma glucose was significantly higher in HSD fed rats only at 3 but not 6 months of feeding. These results suggest that HSD feeding aggravated insulin resistance / induced Type 2 Diabetes / in the WNIN/Gr-Ob rats.
Ageing of the Brain
Brain is the master controller of the body which controls the functions of all other organs and Age is a major risk factor for most common neurodegenerative diseases. The functions of different regions in the brain are differentially susceptible to age-induced changes . Indeed, brain ageing can be considered as the death of the functioning brain and indirectly that of the body. Brain ageing is normally expressed in terms of DNA damage which is quantitated by the Comet assay . It was interesting that the total neuronal DNA damage was significantly higher in HSD fed rats than those fed SBD after 3months of feeding. It was interesting that telomere length, a key marker of ageing, was significantly reduced in HSD fed rats compared to SBD fed rats, but only after 6 months of feeding. Indeed our observations that HSD fed rats had increased oxidative stress and decreased antioxidant defense in their brain are in line with our hypothesis and appear to justify the inference that High sucrose feeding to obese rats aggravates DNA damage by increasing their oxidative stress. Overall, these findings suggest that HSD feeding to WNIN/Gr-Ob rats reduces their longevity compared to those fed SBD and increased oxidative stress and the attendant DNA damage may underly this decreased longevity.
Ageing of Liver
Liver is an important metabolically active organ, whose cells turnover rapidly. The rate of ageing of the liver can be determined either by the increased DNA damage and / or decreased repair activity. Morphological and histological changes, ROS are all involved in the ageing of liver . Histologically, increased hepatic steatosis was observed in WNIN/Gr-Ob rats fed HSD at both the time points of feeding studied, compared to their counterparts fed SBD. Increased macromolecular damage was observed in these livers as evident from the increase in lipid peroxidation and protein carbonyl levels observed and a significant decrease in their antioxidant status, the defense mechanism that is essential to cope up with the increased oxidative stress. In addition, there was impaired DNA repair activity in these livers as evident from the significant decrease in the gap repair activity determined using synthetic labeled duplex DNA. Since reduced telomere length is considered to be the direct evidence linking obesity and accelerated ageing , the significant decrease observed in the telomere length of liver DNA from HSD fed rats compared to those fed SBD is in line with and confirms the reduced longevity of the HSD fed rats as determined by the Kaplan Meier plots earlier.
In mammals telomere is the terminal cap of the cells and it protects the cells from degradation. Telomere length is the well established biomarker of ageing. The length of the telomere varies with age. But in diseased conditions and in metabolic syndrome, the telomere length is affected. Considering this fact, we measured telomere length in brain, liver and neuronal cells of WNIN/Gr-Ob rats fed HSD and SBD fed control rats after 3 and 6 months of feeding their respective diets (Figure 1). We observed that there were differences between organs in the lengths of telomere and the telomere length was significantly reduced with age in the brain and liver of WNIN/Gr-Ob rats fed HSD after feeding for 6 months than those fed SBD . The observed is reduction in telomere length appears to support the inference that increased total neuronal DNA damage may underlie the reduced lifespan of HSD fed WNIN/Gr-Ob rats.
A. Telomere lengths in Liver
B. Telomere lengths in brain
C. Telomere lengths in Isolated Neuronal cells
Figure 1: Telomere lengths in different groups of rats after 3 and 6 months of feeding their respective diets.
From our observations we conclude that inducing T2D / aggravating insulin resistance in the WNIN/Gr-Ob obese rats by high sucrose feeding reduced their longevity. Increased macromolecular (lipids, protein and DNA) damage most probably due to increased oxidative stress and / or impaired antioxidant status appear to be the underlying / associated mechanism.
We acknowledge DBT for funding the project (BT/PR 3404/FNS/20/529/2011), NIN/NCLAS (ICMR) for the supply of animals.