Ganga Sahay Meena

Sour buttermilk is formed when milk fat is conserved as clarified fat using a traditional household method. It has low total solids (TS) and high acidity. Often, people discard sour buttermilk due to a lack of an effective preservation method. This investigation aimed to concentrate sour buttermilk using nanofiltration (NF) equipped with a 200 Da molecular weight cut-off polyamide membrane (AFC 40), tubular B1 parallel flow module, operated at 20 ± 1 bar pressure and 35 ± 1 °C temperature. The process yielded an NF retentate with 19.61% total solids. The retentate was then spray dried at 185/75 ± 5 °C to produce sour buttermilk powder. This powder showed excellent wettability (3 s, instant) and flowability. The NF permeate contained 0.42 ± 0.05% TS, 0.12 ± 0.03% ash, 0.37 ± 0.02% lactic acidity, and 1.79 ± 0.21 mPa.s apparent viscosity at 20 °C. It was used as a natural coagulant to prepare heat and acid-coagulated milk gel ( chhana ) from buffalo milk. Usually, buffalo milk chhana has a hard texture and grainy body. When prepared with NF permeate, buffalo milk chhana had significantly ( p < 0.05) lower hardness and higher yield compared to cow milk chhana made with citric acid. Overall, this investigation showed that NF and spray drying can sustainably valorize sour buttermilk with zero waste generation.

Background: The demand for milk protein concentrate (MPC) has increased in recent years due to its high nutritional and functional properties as a food ingredient. However, the application of MPC is restricted due to its higher calcium and casein content, which lowers its solubility. Aim: This study investigated the effect of high shear treatment and addition of sodium bicarbonate to ultrafiltered retentate on the physicochemical, solubility and functional properties of milk protein concentrate prepared therefrom. Methods: Skim milk was ultrafiltered through a 50 kDa ceramic membrane. The obtained ultrafiltered retentate was added to sodium bicarbonate and homogenised using a high‐shear mixer. Milk protein concentrate was prepared by spray drying the ultrafiltered retentate added to sodium bicarbonate (MPC‐SC). A control was prepared from ultrafiltered retentate without any treatment (MPC). Major Findings: MPC‐SC exhibited higher interstitial air content and occluded air content than MPC. Sodium bicarbonate addition and high shear treatment improved the reconstitutional properties including wettability, dispersibility and solubility. Functional properties of MPC‐SC such as water and oil binding capacity, foaming capacity and emulsification stability were significantly ( P < 0.05) higher than MPC. With increasing shear rate, reconstituted MPC and MPC‐SC showed shear‐thinning behaviour. Scanning electron micrographs revealed smooth and round surfaces of MPC‐SC particles, while MPC had damaged, wrinkled or irregular surfaces. The increase in pH enhances the negative charge on the phosphoserine residues and disrupts the casein micelles, resulting in smaller molecules that repel each other, thus improving solubility and functional properties of MPC‐SC. Sensory attributes exhibited nonsignificantly ( P > 0.05) higher scores for MPC‐SC than MPC. Scientific Implications: The results indicate that the addition of alkali and high shear treatment of ultrafiltered retentate could effectively improve the functional properties of MPC. MPC with improved solubility could be used for standardisation of protein content in dairy products such as cheese and yoghurt.

Background: Processed cheese products (PCP) require precise textural and rheological properties for consumer acceptability. Hydrocolloids such as κ‐carrageenan (KC), guar gum (GG) and xanthan gum (XG) are commonly used to modify these attributes.Context: The influence of KC, GG and XG at varying concentrations (0.1, 0.2 and 0.3%) on the physicochemical, functional, textural and rheological properties of PCP formulated with milk protein concentrate 80 (MPC80) was investigated.Aim: This study aimed to evaluate the effect of different hydrocolloids on oiling off, meltability, textural characteristics and rheological behaviour of PCP, with the goal of identifying the optimal hydrocolloid type and concentration for improving product quality.Methods: The physicochemical properties, functional properties including oiling off and meltability, were assessed. Texture analysis measured hardness variations based on hydrocolloid concentration. Rheological properties, including storage modulus (G′) and loss modulus (G″), were analysed through frequency and temperature sweep tests to determine structural behaviour.Major Findings: PCP samples with XG and GG showed no oiling off, whereas the PCP with XG showed better meltability and flowability. Textural analysis indicated that hardness escalated as the addition level of hydrocolloids increased. PCP containing XG at 0.3% level showed desirable hardness compared with control processed cheese. Rheological measurements showed that both the storage and loss modulus increased with angular frequency, indicating a more compact structure. The temperature sweep analysis of all PCP samples demonstrated behaviour characteristic of melting.Conclusion: This study proposes that incorporating XG at a level of 0.3% during the production of PCP using MPC80 and butter could yield a processed cheese‐like product with improved textural matrix, functional and rheological attributes.

Reverse osmosis (RO) is known for the economic dewatering of dairy streams without any change in phase. At the household level, surplus milk is fermented and churned to obtain butter, which is subsequently heated to obtain clarified milk fat (ghee). The production of 1 kg ghee generates 15–20 kg sour buttermilk (SBM) as a by-product that is mostly drained. This causes a loss of milk solids and environmental pollution. The processing, preservation and valorization of SBM are quite challenging because of its low total solids (TS) and pH, poor heat stability and limited shelf life. This investigation aimed to transform SBM into a novel dried dairy ingredient. SBM was thermized, filtered, defatted and concentrated at 35 ± 1 °C, employing RO up to 3.62× (12.86%). The RO concentrate was subsequently converted into sour buttermilk powder (SBMP) by employing spray drying. SBMP was further characterized for its physicochemical, reconstitution and functional properties; rheological and morphological characteristics; and amino acid and fatty acid profiling, along with FTIR and XRD spectra. SBMP was “instant soluble-3 s” and exhibited excellent emulsion stability (80.70%), water binding capacity (4.34 g/g of protein), flowability (28.36°) and antioxidant properties. In nutshell, a process was developed for the valorization of sour buttermilk to a novel dairy ingredient by employing reverse osmosis and a spray-drying process.

As compared to age, intact casein in the natural cheddar cheese is a better index of selection for manufacturing processed cheese. In view of this, the pre

Ultrafiltration (UF) of buffalo skim milk (BSM) induces changes in its delicate protein-mineral equilibrium. Appling UF causes alteration in chemical composition of UF retentates as a function of protein concentration that adversely affect their physical and rheological properties. Hence, present investigation was targeted to evaluate the changes taking place in heat stability, ζ-potential, particle size, apparent viscosity, pH, turbidity and crossover temperature of storage (G′) and loss (G″) modulus of high-protein BSM based UF retentates as a function of homogenization and sodium hydrogen phosphate (SHP) addition. The UF of BSM (heat treated at 85 ± 1 °C for 5 min), significantly increased (P < 0.05) the concentration of protein, fat and minerals, however, it decreased the concentration of lactose and water soluble minerals in UF retentates over BSM. The SHP addition significantly increased (P < 0.05) pH, crossover temperature of G′ and G″, ζ-potential, while significantly decreased (P < 0.05) turbidity and particle size in most non-homogenized retentates. Heat coagulation time (HCT) of control and treated UF retentates were at par (P > 0.05) with each other, however, variations were observed in their viscosity values. Rheological behaviour of most of these UF retentates was efficiently described by Bingham model. The correlation among ζ-potential, particle size, apparent viscosity, pH, turbidity, HCT and crossover temperatures G′ and G″ of evaluated samples was also established. Overall, this study concluded that 0.5–6% SHP addition in non-homogenized UF retentates, markedly improved their milk protein stability as advocated by higher ζ-potential, G′ and G″ crossover temperature values.

The Indian dairy industry is highly diversified in terms of milk production, collection, processing and waste disposal. Membrane processing allows dairy sector to manufacture high quality nutritive dairy products at lower costs with minimum water use and product losses. Compared to prevailing traditional methods of milk concentration, reverse osmosis (RO) is still evolving, finding newer applications in dairy processing because of its potential benefits. A brief overview of RO, membranes, process variables, fouling, merits and demerits along with potential suppliers and membrane utilizing dairy plants in India are systematically presented in this review. Different applications of RO in dairy industry including concentration of liquid dairy streams, further utilization of RO retentate in formulation of ice-cream, dahi, traditional Indian dairy products, cheese and dried powders is also included. RO can play a prominent role in Indian dairy sector for simplifying the process automation, product diversification and efficient waste utilization.

Ultrafiltration and Diafiltration processes are used to concentrate proteins present in defatted milk in order to manufacture milk protein concentrate (MPC) powders. Selective passage of the water-soluble components causes retention as well as concentration of colloidal milk components in these processes. Increase in calcium and casein contents decreases the stability of milk proteins present in ultrafiltered retentates and negatively influence properties of manufactured MPC powders. Homogenization, diafiltration and disodium phosphate induced changes in properties of low-protein MPC powders were targeted in this study. Applied treatments significantly (P < 0.05) improved foaming and emulsification, solubility, viscosity, heat stability, dispersibility, specific surface area and buffer index of resultant MPC powders over control. Fresh, treated low-protein MPC powders showed significantly higher (< 0.05) solubility values over control sample, which remains higher even after 60 days of storage at 25 ± 1 °C. The rheological behaviour of reconstituted low-protein MPC solutions was also studied. It was best explained as Herschel–Bulkley rheological behaviour. Low-protein MPC powders with improved functional properties may find better use as a protein ingredient in different dairy and food applications.

Milk protein concentrate (MPC) powders are high-protein, innovative dairy ingredients. Buffalo milk naturally contains higher concentrations of casein and calcium, which have adverse effect on solubility of MPC powders. Therefore, this study was undertaken to investigate the effect of Sodium triphosphate (STP) and Sodium hexametaphosphate (SHMP) addition in ultrafiltered retentate on physicochemical, functional and reconstitution properties, morphological characteristics and rheological behaviour of the resultant powder. Pasteurized buffalo skim milk (PBSM) was concentrated by ultrafiltration (UF) process to obtain 2.53 × UF retentate (2.53 × UFR) with 0.61 protein to total solids (TS) ratio. Compared to PBSM, ultrafiltration significantly increased (p < 0.05) calcium, protein and TS contents of 2.53 × UFR, but significantly decreased (p < 0.05) its heat stability. Addition of STP–SHMP mixture in 2.53 × UFR noticeably improved the solubility, flowability, water binding, oil binding, foaming capacity, foam and thermal stability and, viscosity of treated MPC60 powder over control powder. The DeBroukere (D₄₃) mean, d₅₀, specific surface area, span and water activity values of treated MPC60 powder were 94.96 ± 0.05, 78.33 ± 0.04 µm, 715.93 ± 0.29 m² kg⁻¹, 1.97 ± 0.01 and, 0.26 ± 0.01, respectively. Scanning electron micrograph showed the presence of different size powder particles without clustering. Rheological modelling of the reconstituted solution of treated MPC60 was very well described by Herschel–Bulkley model. Overall, this study established that addition of STP–SHMP salts mixer in 2.53 × UFR could improve the solubility of resultant buffalo milk based MPC60 powder.