Impact of novel processing techniques on the functional properties of egg products and derivatives: a review

Eggs are an excellent source of quality proteins. Eggs as a whole and its components (egg white and egg yolk) are employed in a range of food preparations. Thermal processing employed for stabilizing and improving shelf‐life of egg components is known to have adverse effect on heat‐sensitive proteins leading to protein denaturation and aggregation thus, reducing the required functional, technological, and overall quality of egg proteins and other constituents. Therefore, the current challenge is to identify novel processing techniques that not only improve the intrinsic functional properties of eggs or its components, but also improve the quality of the product. This review focuses on the use of technologies such as ultrasound, pulsed electric field, high‐pressure processing, radiofrequency, ultraviolet light, microwave, and cold plasma for egg products. These novel technologies are known for their advantages over thermal treatments especially in protecting the heat sensitive nature and retaining the overall quality of the egg and egg products. Availability of alternatives processing has significantly improved the structural properties, techno‐functional, nutritional and as well improving the safety egg and egg products. PRACTICAL APPLICATION: Eggs are consumed worldwide as whole egg or in some cases, consumed partly as egg whites or egg yolks. Egg components with improved techno‐functional properties can be used in various food industries (such as baking, confectionery, and culinary preparation, etc.). Value addition of new products can be achieved through modification of egg proteins. Additionally, these techniques also provide microbial safety and have a reduced impact on nutritional content and overall food quality

Effect of iron-fortified jamun leather on the Asunra-induced anemia in Sprague Dawley rats

IntroductionMicronutrients such as minerals and vitamins are required in a minute quantity but play a pivotal role in the functioning of the body. Therefore, deficiency in one of them can lead to lethal health conditions. Iron deficiency anaemia is one of the most common micronutrient deficiencies across the world and is affecting women and children.MethodsThe present study aimed to investigate the anti-anaemic effect of fortified jamun leather on anaemia biomarkers and haematology in anaemic female Sprague Dawley rats. A total of 40 Sprague Dawley rats were used in 4 groups. Iron deficiency anaemia was induced by oral administration of the Asunra drug. The treatments were fed at two dosage levels i.e., 40 and 60% iron-fortified leather. All animals were treated for 60 days and the parameters including biochemical, and histopathology of the kidney and liver were examined.ResultsThe experiment's findings showed that the group fed with iron-fortified leather (G3) succeeded significantly (P < 0.05) in restoring the serum iron (98.68 ± 2.88 μg/dL), haemoglobin (12.41 ± 0.32 g/dL), ferritin (24.54 ± 1.98 ng/mL) and haematocrit levels (39.30 ± 1.66%) at the end of the 60 days period. Additionally, the treated group's mean values for transferrin and total iron binding capacity were lower than those of the anaemic rats, indicating an improvement in iron levels. The microscopic analysis revealed that treatments had no toxic effects on the kidney and liver tissues, except in the diseased group, which had necrosis and irregular cell structure.ConclusionConclusively, iron-fortified jamun leather helped improve iron deficiency biomarkers and imparted a non-toxic effect on tissues in rats

Profiling of anti-oxidative enzymes and lipid peroxidation in leaves of salt tolerant and salt sensitive maize hybrids under NaC1 and Cd stress

Effects of NaCl salinity and cadmium on the anti-oxidative activity of enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and lipid peroxidation contents; malondialdehyde (MDA) were studied in two maize hybrids of different salt tolerance characteristics. An increase in the amount of lipid peroxidation indicated the oxidative stress induced by NaCl and Cd. The results also depicted that NaCl stress caused an increase in the activities of POD, SOD, CAT, APX and GR while cadmium stress increased the activities of POD, SOD and APX but showed no significant effect on CAT and GR in both the studied hybrids. The combined effect of salinity and cadmium on these parameters was higher than that of sole effect of either NaCl or Cd. It was also found that maize hybrid 26204 had better tolerance against both stresses with strong antioxidant system as compared to that of maize hybrid 8441. A comparison of the antioxidants and lipid peroxidation in two maize hybrids having varying level of NaCl and Cd stress tolerance corroborated the importance of reactive oxygen species (ROS) in defense against abiotic stresses

Punicic acid: A striking health substance to combat metabolic syndromes in humans

Abstract Punicic acid, a bioactive compound of pomegranate seed oil has gained wide attention for their therapeutic potential. Different studies conducted on animal and human models have revealed that punicic acid is very effective against various chronic diseases. Substantial laboratory works has been carried out to elaborate punicic acid effectiveness and mechanism of action in animals. The intention of this review article is to explore the facts about the clinical trials of punicic acid and to discuss different future strategies that can be employed to use it in human clinical trials. Although punicic acid may represent a novel therapeutic unconventional approach for some disorders, still further experimental studies are required to demonstrate its effects in human beings

Influence of selected hydrocolloids on the rheological, functional, and textural properties of wheat‐pumpkin flour bread

International audienc

Channelling eggshell waste to valuable and utilizable products: A comprehensive review

International audienc

Microfiltration, a processing technology to have safe, sure buffalo dairy products with their natural quality

Pakistan is the third largest milk producer and second largest buffalo milk producer in the world. Buffalo milk is the second produced milk with a contribution of 12.7% in the world’s milk production. More than 92% of this milk is being contributed by India and Pakistan. This milk is richer in protein particularly casein i.e. 34-36 g.kg-1, equivalent to the total protein contents of cow milk. Casein represents 80% of the total protein of both milks and find as colloidal particles called casein micelles. In buffalo milk, casein micelles are bigger in size, more mineralized and less hydrated but with similar charge as compared to its counter part cow milk (Ahmad et al, 2008a and b). In spite of the important production of buffalo milk, the technological transformations of this milk into dairy products are very limited as compared to cow milk. Some cheeses or fermented milks like Cheddar, Mozarella, lassi and yoghurts are manufactured from this milk. Protein ingredients manufactured from buffalo milk such as caseinates associated with different minerals and purified whey proteins are absent on the dairy industrial market. One possible way to obtain these types of ingredients from buffalo milk is to use cross-flow microfiltration. This operation is widely used in the dairy industry for the fractionation of casein micelles and whey proteins from cow milk (Maubois, 1991; Saboya and Maubois, 2000; Nelson and Barbano, 2005). This process produces a retentate enriched in casein micelles with a purity expressed as the ratio [casein]/[total protein] higher than 0.90 (Fauquant et al, 1988; Pierre et al, 1992; Schuck et al, 1994). The technological behaviours of these purified casein micelles during acidification, rennet coagulation and heat treatment are also very similar to milk. For these reasons, these casein micelles purified by cross-flow microfiltration are considered as native. The objectives of this work were to apply cross-flow microfiltration (0.1 µm) firstly, to have bacteria free buffalo milk without any heat treatment, secondly to isolate and characterize the casein micelles from buffalo milk. For this purpose, cream and bacteria from milks were removed at 50°C through a cream separator and microfiltration (1.4 µm), respectively. Casein micelles were then separated and concentrated through cross-flow microfiltration (0.1 µm) followed by purification through four volume water and again concentrated through water removal. Purification was performed in three main steps: concentration of casein micelles, diafiltration of retentate and final concentration (Fig. 1). The products obtained at different steps of the process were analysed for pH, total solids, proteins fractions, minerals contents and as well for size, zeta potential and hydration of casein micelles. Figure 1: Technological scheme for the purification of casein micelles from buffalo and cow milk by cross-microfiltrations (pore size of 1.4 and 0.1 μm). Microbiological analyses of raw skimmed milk and bacteria free milk after the first microfiltration (1.4 µm) showed a great reduction of coliforms and FMAR in both milks (Table 1) so the first objective was well achieved. Table 1: Coliforms and FMAR counts Milk Coliforms FMAR Raw buffalo skimmed milk 3.3×101 7.5×101 Microfiltered buffalo milk <1 1.5×101 Raw cow skimmed milk 9.7×104 3.2×104 Microfiltered cow milk <1 6.5×101 As the second objective of this study was to purify casein micelles from buffalo milk by cross-flow microfiltration, so the results have been described and discussed for each step during the process. The biochemical compositions and physico-chemical characteristics of initial bacteria-free skimmed milks and the different retentates (intermediate, diafiltered and final) have been reported as under. Results obtained with buffalo milk were compared to cow milk and discussed. Bacteria-free skimmed milks: The contents in total protein and casein were higher for buffalo milk than that of cow milk. However, in both milks, casein content as compared to the total protein content corresponded to similar percentage i.e. 80 %. To know more about the differences in the composition between buffalo and cow milk, it was interesting to compare the different ratios. The ratios [total protein]/[total solid], [casein]/[total solid] and [casein]/[whey protein] were 0.41, 0.35 and 5.3 for buffalo milk and 0.35, 0.27 and 4.5 for cow milk, respectively. From these ratios, it is evident that the protein contents of buffalo milk were different than that of cow milk. The total and micellar calcium (Ca) and inorganic phosphate (Pi) concentrations were higher in buffalo milk than in cow milk as also observed by Ahmad et al. (2008a). The pH values of both milks were close to pH 6.7. The size of casein micelles from buffalo milk was higher, the zeta potential was similar and the micellar hydration was lower than that of cow milk and as described by Ahmad et al. (2008a). Intermediate retentates: The contents in total protein and casein were increased for both intermediate retentates in comparison with initial skimmed milks. A slight retention of whey proteins in the intermediate retentate for cow milk compared to buffalo milk was observed. The ratios [total protein]/[total solid] increased up to 0.54 and 0.57 for intermediate retentates of buffalo and cow milk, respectively. At the same time, the ratios [casein]/[whey proteins] increased from about 5 for both initial milks to about 10 for both intermediate retentates. These calculated ratios indicated that the purifications of casein micelles were in progress in a similar way for both milks. The total Ca and Pi concentrations increased by 1.7 and 1.6 times for intermediate retentates of buffalo milk, and by 2.3 and 2.1 times for intermediate retentates of cow milk, respectively in comparison with milks. As discussed with the non protein nitrogen compounds, minerals and ions H+ were also able to pass through the membrane and consequently their concentrations were the same in retentate and permeate. Diafiltered retentates: The contents in non casein nitrogen, non protein nitrogen, whey protein, Ca and Pi were strongly reduced. During the diafiltration, the major part of the soluble compounds present in the aqueous phase of retentates like lactose, minerals, whey proteins and small molecules were removed. The concentration of whey proteins was lower in diafiltered retentate of buffalo milk than that of cow milk. This difference indicated that the whey proteins of buffalo milk were more easily transmitted than cow milk. On the other hand, the contents in total solids of these diafiltered retentates were strongly reduced. During diafiltration, 50.3 and 54.5 g.kg-1 of total solid contents was removed from buffalo and cow milk, respectively. At the end of diafiltration, the total solid corresponded essentially to casein micelles containing minerals. These ratios indicated that diafiltration was particularly efficient to increase the level of purity of casein micelles for both milks. At the same time, the ratios [casein]/[whey proteins] were about 42.3 and 26.7 for diafiltered retentates of buffalo and cow milk, respectively suggesting a good and best elimination of the whey proteins in the diafiltered retentates of buffalo milk in comparison with those of cow milk. The pH values of both diafiltered retentates increased in a similar way by about 0.6 units. The reduction of the ionic strength and especially Pi and citrate from the aqueous phase due to the diafiltration explained theses increases in pH. Indeed, these ions contribute to the buffering capacity of milk and their removals during the diafiltration step led to an increase in pH. The micellar characteristics of both diafiltered retentates were affected in comparison with those determined for milks and intermediate retentates. The zeta potentials of casein micelles from both retentates were more negative after diafiltration. These were related to the increase in pH and to the reduction in the ionic concentration of the aqueous phase induced by diafiltration. Final retentates: The contents in total solid, total protein and casein were increased in comparison with the corresponding intermediate and diafiltered retentates. The ratios [total protein]/[total solid] were 0.86 and 0.89 for final retentates of buffalo and cow milk, respectively. For the cow milk, the ratio obtained in this work was in accordance with the published values of 0.84 (Pouliot et al., 1994), 0.86-0.88 (Pierre et al., 1992) and 0.90 (Schuck et al., 1994). The ratios [casein]/[total solid], [casein]/[total protein] and [casein]/[whey protein] were 0.84, 0.98 and 45 for final retentate of buffalo milk against 0.86, 0.96 and 27 for final retentate of cow milk. The last calculated ratio confirmed the slight retention of whey proteins for cow milk compared to buffalo milk. Two possible reasons can explain this difference of filtration. Firstly, the composition and structures of the whey proteins from buffalo milk are different and consequently their capacities to be microfiltered were also different. The other reason concerns the formation of a fouling layer at the membrane surface during filtration. These different calculated ratios showed that the level of purification of casein micelles of buffalo milk by cross-flow microfiltration was correct and satisfactory. 98-99% of Ca and Pi were associated to casein micelles in both final retentates. Micellar zeta potentials were always more negative as compared to casein micelles of milks because the aqueous phase became very poor in minerals. Conclusions: This study showed that the safe and microbial free buffalo milk can be obtained through cross-flow microfiltration without involving heat and without modifying the nature and nutritional quality of milk. So microfiltration can be considered as a processing technology to have safe, sure buffalo dairy products with their natural quality. It also showed that purification of casein micelles from buffalo milk was possible like cow milk without any major problem. The biochemical analyses of the final retentate of buffalo milk showed that it contained mainly casein and minerals and that the different compounds present in the aqueous phase were well removed. These ingredients can be used in different formulations for Ca and phosphate enrichments

Microfiltration, a processing technology to have safe, sure buffalo dairy products with their natural quality

Pakistan is the third largest milk producer and second largest buffalo milk producer in the world. Buffalo milk is the second produced milk with a contribution of 12.7% in the world’s milk production. More than 92% of this milk is being contributed by India and Pakistan. This milk is richer in protein particularly casein i.e. 34-36 g.kg-1, equivalent to the total protein contents of cow milk. Casein represents 80% of the total protein of both milks and find as colloidal particles called casein micelles. In buffalo milk, casein micelles are bigger in size, more mineralized and less hydrated but with similar charge as compared to its counter part cow milk (Ahmad et al, 2008a and b). In spite of the important production of buffalo milk, the technological transformations of this milk into dairy products are very limited as compared to cow milk. Some cheeses or fermented milks like Cheddar, Mozarella, lassi and yoghurts are manufactured from this milk. Protein ingredients manufactured from buffalo milk such as caseinates associated with different minerals and purified whey proteins are absent on the dairy industrial market. One possible way to obtain these types of ingredients from buffalo milk is to use cross-flow microfiltration. This operation is widely used in the dairy industry for the fractionation of casein micelles and whey proteins from cow milk (Maubois, 1991; Saboya and Maubois, 2000; Nelson and Barbano, 2005). This process produces a retentate enriched in casein micelles with a purity expressed as the ratio [casein]/[total protein] higher than 0.90 (Fauquant et al, 1988; Pierre et al, 1992; Schuck et al, 1994). The technological behaviours of these purified casein micelles during acidification, rennet coagulation and heat treatment are also very similar to milk. For these reasons, these casein micelles purified by cross-flow microfiltration are considered as native. The objectives of this work were to apply cross-flow microfiltration (0.1 µm) firstly, to have bacteria free buffalo milk without any heat treatment, secondly to isolate and characterize the casein micelles from buffalo milk. For this purpose, cream and bacteria from milks were removed at 50°C through a cream separator and microfiltration (1.4 µm), respectively. Casein micelles were then separated and concentrated through cross-flow microfiltration (0.1 µm) followed by purification through four volume water and again concentrated through water removal. Purification was performed in three main steps: concentration of casein micelles, diafiltration of retentate and final concentration (Fig. 1). The products obtained at different steps of the process were analysed for pH, total solids, proteins fractions, minerals contents and as well for size, zeta potential and hydration of casein micelles. Figure 1: Technological scheme for the purification of casein micelles from buffalo and cow milk by cross-microfiltrations (pore size of 1.4 and 0.1 μm). Microbiological analyses of raw skimmed milk and bacteria free milk after the first microfiltration (1.4 µm) showed a great reduction of coliforms and FMAR in both milks (Table 1) so the first objective was well achieved. Table 1: Coliforms and FMAR counts Milk Coliforms FMAR Raw buffalo skimmed milk 3.3×101 7.5×101 Microfiltered buffalo milk <1 1.5×101 Raw cow skimmed milk 9.7×104 3.2×104 Microfiltered cow milk <1 6.5×101 As the second objective of this study was to purify casein micelles from buffalo milk by cross-flow microfiltration, so the results have been described and discussed for each step during the process. The biochemical compositions and physico-chemical characteristics of initial bacteria-free skimmed milks and the different retentates (intermediate, diafiltered and final) have been reported as under. Results obtained with buffalo milk were compared to cow milk and discussed. Bacteria-free skimmed milks: The contents in total protein and casein were higher for buffalo milk than that of cow milk. However, in both milks, casein content as compared to the total protein content corresponded to similar percentage i.e. 80 %. To know more about the differences in the composition between buffalo and cow milk, it was interesting to compare the different ratios. The ratios [total protein]/[total solid], [casein]/[total solid] and [casein]/[whey protein] were 0.41, 0.35 and 5.3 for buffalo milk and 0.35, 0.27 and 4.5 for cow milk, respectively. From these ratios, it is evident that the protein contents of buffalo milk were different than that of cow milk. The total and micellar calcium (Ca) and inorganic phosphate (Pi) concentrations were higher in buffalo milk than in cow milk as also observed by Ahmad et al. (2008a). The pH values of both milks were close to pH 6.7. The size of casein micelles from buffalo milk was higher, the zeta potential was similar and the micellar hydration was lower than that of cow milk and as described by Ahmad et al. (2008a). Intermediate retentates: The contents in total protein and casein were increased for both intermediate retentates in comparison with initial skimmed milks. A slight retention of whey proteins in the intermediate retentate for cow milk compared to buffalo milk was observed. The ratios [total protein]/[total solid] increased up to 0.54 and 0.57 for intermediate retentates of buffalo and cow milk, respectively. At the same time, the ratios [casein]/[whey proteins] increased from about 5 for both initial milks to about 10 for both intermediate retentates. These calculated ratios indicated that the purifications of casein micelles were in progress in a similar way for both milks. The total Ca and Pi concentrations increased by 1.7 and 1.6 times for intermediate retentates of buffalo milk, and by 2.3 and 2.1 times for intermediate retentates of cow milk, respectively in comparison with milks. As discussed with the non protein nitrogen compounds, minerals and ions H+ were also able to pass through the membrane and consequently their concentrations were the same in retentate and permeate. Diafiltered retentates: The contents in non casein nitrogen, non protein nitrogen, whey protein, Ca and Pi were strongly reduced. During the diafiltration, the major part of the soluble compounds present in the aqueous phase of retentates like lactose, minerals, whey proteins and small molecules were removed. The concentration of whey proteins was lower in diafiltered retentate of buffalo milk than that of cow milk. This difference indicated that the whey proteins of buffalo milk were more easily transmitted than cow milk. On the other hand, the contents in total solids of these diafiltered retentates were strongly reduced. During diafiltration, 50.3 and 54.5 g.kg-1 of total solid contents was removed from buffalo and cow milk, respectively. At the end of diafiltration, the total solid corresponded essentially to casein micelles containing minerals. These ratios indicated that diafiltration was particularly efficient to increase the level of purity of casein micelles for both milks. At the same time, the ratios [casein]/[whey proteins] were about 42.3 and 26.7 for diafiltered retentates of buffalo and cow milk, respectively suggesting a good and best elimination of the whey proteins in the diafiltered retentates of buffalo milk in comparison with those of cow milk. The pH values of both diafiltered retentates increased in a similar way by about 0.6 units. The reduction of the ionic strength and especially Pi and citrate from the aqueous phase due to the diafiltration explained theses increases in pH. Indeed, these ions contribute to the buffering capacity of milk and their removals during the diafiltration step led to an increase in pH. The micellar characteristics of both diafiltered retentates were affected in comparison with those determined for milks and intermediate retentates. The zeta potentials of casein micelles from both retentates were more negative after diafiltration. These were related to the increase in pH and to the reduction in the ionic concentration of the aqueous phase induced by diafiltration. Final retentates: The contents in total solid, total protein and casein were increased in comparison with the corresponding intermediate and diafiltered retentates. The ratios [total protein]/[total solid] were 0.86 and 0.89 for final retentates of buffalo and cow milk, respectively. For the cow milk, the ratio obtained in this work was in accordance with the published values of 0.84 (Pouliot et al., 1994), 0.86-0.88 (Pierre et al., 1992) and 0.90 (Schuck et al., 1994). The ratios [casein]/[total solid], [casein]/[total protein] and [casein]/[whey protein] were 0.84, 0.98 and 45 for final retentate of buffalo milk against 0.86, 0.96 and 27 for final retentate of cow milk. The last calculated ratio confirmed the slight retention of whey proteins for cow milk compared to buffalo milk. Two possible reasons can explain this difference of filtration. Firstly, the composition and structures of the whey proteins from buffalo milk are different and consequently their capacities to be microfiltered were also different. The other reason concerns the formation of a fouling layer at the membrane surface during filtration. These different calculated ratios showed that the level of purification of casein micelles of buffalo milk by cross-flow microfiltration was correct and satisfactory. 98-99% of Ca and Pi were associated to casein micelles in both final retentates. Micellar zeta potentials were always more negative as compared to casein micelles of milks because the aqueous phase became very poor in minerals. Conclusions: This study showed that the safe and microbial free buffalo milk can be obtained through cross-flow microfiltration without involving heat and without modifying the nature and nutritional quality of milk. So microfiltration can be considered as a processing technology to have safe, sure buffalo dairy products with their natural quality. It also showed that purification of casein micelles from buffalo milk was possible like cow milk without any major problem. The biochemical analyses of the final retentate of buffalo milk showed that it contained mainly casein and minerals and that the different compounds present in the aqueous phase were well removed. These ingredients can be used in different formulations for Ca and phosphate enrichments