Advanced methods of algal pigments extraction: A review.

Algae are exclusively aquatic photosynthetic organisms that are microscopic or macroscopic, unicellular or multicellular and distributed across the globe. They are a potential source of food, feed, medicine and natural pigments. A variety of natural pigments are available from algae including chlorophyll a, b, c d, phycobiliproteins, carotenes and xanthophylls. The xanthophylls include acyloxyfucoxanthin, alloxanthin, astaxanthin, crocoxanthin, diadinoxanthin, diatoxanthin, fucoxanthin, loroxanthin, monadoxanthin, neoxanthin, nostoxanthin, perdinin, Prasinoxanthin, siphonaxanthin, vaucheriaxanthin, violaxanthin, lutein, zeaxanthin, ß-cryptoxanthin, while carotenes include echinenone, α-carotene, ß-carotene, γ-carotene, lycopene, phytoene, phytofluene. These pigments have applications as pharmaceuticals and nutraceuticals and in the food industry for beverages and animal feed production. The conventional methods for the extraction of pigments are solid-liquid extraction, liquid-liquid extraction and soxhlet extraction. All these methods are less efficient, time-consuming and have higher solvent consumption. For a standardized extraction of natural pigments from algal biomass advanced procedures are in practice which includes Supercritical fluid extraction, Pressurized liquid extraction, Microwave-assisted extraction, Pulsed electric field, Moderate electric field, Ultrahigh pressure extraction, Ultrasound-assisted extraction, Subcritical dimethyl ether extraction, Enzyme assisted extraction and Natural deep eutectic solvents. In the present review, these methods for pigment extraction from algae are discussed in detail.

Physical, chemical, microbial, and sensory evaluation and fatty acid profiling of value-added drinking yogurt (laban) under various storage conditions.

Yogurt is defined as a coagulated milk product obtained from the fermentation of lactose into lactic acid. Drinking yogurt (laban) was prepared from buffalo milk, cow milk, and a 50:50 blend (cow + buffalo milks) by adding 0.5% carboxymethyl cellulose to each of the 3 milk treatments. Samples were then refrigerated for 7, 14, and 21 d before determination of physical, microbial, and sensory parameters. Yogurt prepared from buffalo milk had higher fat and protein contents, and better taste, aroma, and overall consumer acceptability compared with laban prepared from cow milk or mixed milk. During storage, protein and total solids contents remained unchanged, whereas milk fat, color, appearance, taste, smell, texture, and overall acceptability of laban decreased in the different treatment groups. The acidity of laban increased with storage time. Bacteria, including coliforms, were not found in any treatment group during storage. In conclusion, overall acceptability of laban prepared from buffalo milk was higher than that made from cow milk or mixed milk, but increased storage time reduced the quality of laban prepared from cow, buffalo, or mixed milk.

Preventive role of propolis against hyperglycemia and hyperlipidemia in Sprague dawley rats (Rattus norvegicus) animal modelling system.

Human diets with functional ingredients showed promising role in management of diseases of modern age like hyperglycemia and hyperlipidemia and even cancer. The study designed to elucidate role of honeybee propolis for management of hyperglycemia and hyperlipidemia states through animal modeling system. Hydroalcoholic extract of propolis was used for development of functional drink with standard recipe and addition of specified dose of extracts (400mg/500mL). Animals were grouped into three studies including study-I fed on regular diet, study-II fed on sucrose enrich diet and study-III fed on diet enriched with cholesterol and monitored to evaluate the results. Various parameters like feed consumption, liquid intake of animals measured regularly whereas body weight recorded at the end of each week of study. At the end of the study animals were analyzed for different blood indicators like blood lipid indices (cholesterol, LDL, HDL concentration and triglyceride contents)), glucose concentration and insulin contents as well. The maximum feed and drink intake were examined in animals, fed with control diet whereas a non substantial mode of intake was recorded in rest of two groups of animals. The consumption of honeybee propolis based drink reduced cholesterol (6.63% to 10.25%) and LDL (9.96% to 11.23%), whilst a sharp increase in HDL level was ranged as 4.12 to 4.49% among animal groups fed with high cholesterol and high sucrose diet. Blood glucose level was decreased by 10.25% and 6.98% however 6.99% and 4.51% increase were observed in plasma insulin level in both studies, study-II and study-III correspondingly. The overall findings of the study showed that drinks prepared using propolis of propolis found effective for management of hyperglycemia and hypercholesterolemia in present animal modelling system.

Influence of milling pH and storage on quality characteristics, mineral and fatty acid profile of buffalo Mozzarella cheese.

BACKGROUND: Currently, cheese fat is a major component of human diet due to change in eating habits. It contains a number of health destroying as well as health promoting fatty acids. Bovine milk cheese fatty acid composition is regulating by many factors. These may be breed of animal, animal health condition like mastitis and stage of lactation. It also differs with feed and dietary fat intake and seasons. Many studies demonstrated physicochemical, textural and sensory characteristics of Mozzarella cheese with variation in technological process but no literature found about the fatty acid profile and potential influence of milling pH on the fatty acid composition of buffalo Mozzarella cheese. METHODS: Buffalo Mozzarella cheeses were manufactured at 5.2, 5.1, 5.0, 4.9 and 4.8 milling pH, vacuum packaged and stored at 4 °C and analyzed for quality characteristics, mineral composition and fatty acid profile on days 1, 45, and 90. Results were analyzed by ANOVA according to complete randomized design. RESULTS: This study evaluated the effect of milling pH on chemical composition, mineral and fatty acid profile of buffalo Mozzarella cheese. Experimentally induced milling pH differences persisted and significantly affected chemical composition during first day of manufacturing but have no effect on fatty acid profile of cheese. However, storage effects significantly on chemical composition and fatty acid profile of cheese. Decreasing milling pH from 5.2-4.9 resulted in decrease in moisture content of cheese. As a result of changes in milling pH, all the cheeses experienced a significant loss in protein content. In contrast to protein content, fat content of cheese increases with decreasing milling pH. Ash contents of cheese decreased with decreasing milling pH. The level of calcium decreases from 77.82 mg/g to 69.1 mg/g with decreasing milling pH while there is no clear trend observed for potassium and sodium during change in milling pH. Saturated fatty acids presented higher concentrations reaching values of about 71.38 g/100 g throughout storage while monounsaturated fatty acids decreases with storage from 26.72 to 22.06 g/100 g. On the other hand, total polyunsaturated fatty acids exhibited lower concentrations than total monounsaturated fatty acids reaching values of 3.2 g/100 g and its value also decreased with ripening and reached to 1.6 g/100 g. Concentration of C18:1 t10-11 was observed 1.89% in freshly prepared cheese. Milling pH did not influence C18:1 t10-11 concentration but storage days significantly (p < 0.05) decreased its concentration. CONCLUSION: In modern era, Mozzarella cheese is major source of dietary fatty acids. The study demonstrated that Mozzarella cheese is a rich source of saturated fatty acids that has detrimental effect on health but it is also observed that it is also a major source of essential fatty acids that has beneficial impact on health. It is concluded that technological conditions like milling pH minimally influence cheese fatty acid profile but after manufacturing treatments and conditions like packaging and storage greatly influence fatty acid profile of cheese. It was concluded that cheese may get oxidized if it is packed in inappropriate packaging material that have reduced air barrier resistance. Moreover, cheese storage under light may also become oxidized which is also harmful for health.

Changes in fatty acids composition, antioxidant potential and induction period of UHT-treated tea whitener, milk and dairy drink.

BACKGROUND: In developing and developed countries, several versions of safe and shelf-stable Ultra High Temperature, UHT-treated products are manufactured. Terminologies and formulations of UHT-treated tea whitener, milk and dairy drink considerably vary. Comprehensive studies have been performed on UHT-treated milk; however, fatty acids compositional changes and oxidation status of UHT-treated tea whitener and dairy drink at different storage intervals have not been reported in literature. METHODS: UHT-treated tea whitener, milk and dairy drink samples (450 each) of the same manufacturing date were purchased from the market and stored at ambient temperature (25-30 °C) for 90 days. At the time of collection, all the samples were only one week old. Samples of UHT-treated tea whitener, milk and dairy drink were regarded as treatments and every treatment was replicated five times. Chemical composition, fatty acid profile, 2, 2-Diphenyl-1-picrylhydrazyle (DPPH) radical scavenging activity, total antioxidant activity, reducing power, antioxidant activity in linoleic acid system and induction period were determined at 0, 45 and 90 days of storage. RESULTS: Fat content in freshly collected samples of UHT treated-tea whitener, milk and dairy drink were 6 and 3.5%. UHT treated milk had highest total antioxidant capacity, antioxidant activity in linoleic acid and 2, 2-Diphenyl-1-picrylhydrazyle (DPPH) free radical scavenging activity followed by UHT tea whitener and dairy drink. In freshly collected samples of UHT-treated milk, concentrations vitamin A and E were 0.46 µg/100 g and 0.63 mg/100 g, respectively. UHT-treated tea whitener had the lowest concentrations of vitamin A and E. With the progression of storage period, amount of vitamin A and E decreased. In freshly collected samples, amount of short, medium and unsaturated fatty acids in UHT-treated milk were 10.54, 59.71 and 27.44%, respectively. After 45 days of storage of UHT-treated milk, the loss of short, medium and unsaturated fatty acid was 7%, 7.1 and 5.8%, respectively. After 90 days of storage of UHT-treated milk, the loss of short, medium and unsaturated fatty acid was 8.53, 13.51 and 11.88%, accordingly. After 45 days of storage of UHT-treated tea whitener, the loss of medium and unsaturated fatty acid was 1.6 and 0.99%, respectively. After 90 days of storage, the loss of medium and unsaturated fatty acids were 8.2 and 6.6%, respectively. The induction period of fresh UHT-treated tea whitener, milk and dairy drink was 15.67, .74 and 7.27 h. Strong correlations were recorded between induction period and peroxide value of UHT-treated products. CONCLUSION: This investigation disclosed that UHT-treated tea whitener had 6% fat content with no short-chain fatty acids. Antioxidant capacity of UHT-treated milk was higher than dairy drink and tea whitener. Due to the presence of partially hydrogenated fat, oxidative stability of UHT-treated tea whitener was better than UHT-treated milk and dairy drink. Vitamin A and E was not found in UHT-treated tea whitener. For the anticipation of oxidative stability of UHT-treated milk, dairy drink and tea whitener, induction period/ Rancimat method can be used.

Impact of vitamin E and selenium on antioxidant capacity and lipid oxidation of cheddar cheese in accelerated ripening.

BACKGROUND: Ripening of cheddar cheese is a time taking process, duration of the ripening may be as long as one year. Long ripening time is a big hindrance in the popularity of cheese in developing countries. Further, energy resources in these countries are either insufficient or very expensive. Therefore, those methods of cheese ripening should be discovered which can significantly reduce the ripening time without compromising the quality characteristics of cheddar cheese. In accelerated ripening, cheese is usually ripened at higher temperature than traditional ripening temperatures. Ripening of cheddar cheese at high temperature with the addition of vitamin E and selenium is not previously studied. This investigation aimed to study the antioxidant activity of selenium and vitamin E in accelerated ripening using cheddar cheese as an oxidation substrate. METHODS: The ripening of cheddar cheese was performed at 18 °C and to prevent lipid oxidation, vitamin E and selenium were used alone and in combination. The treatments were as: cheddar cheese without any addition of vitamin E and selenium (T1), cheddar cheese added with 100 mg/kg vitamin E (T2), 200 mg/kg vitamin E (T3), 800 µg/kg selenium (T4), 1200 µg/kg selenium (T5), vitamin E 100 mg/kg + 800 µg/kg selenium (T6) and vitamin E 200 mg/kg + 1200 µg/kg selenium (T7). Traditional cheddar cheese ripne ripened at 4-6 °C for 9 months was used as positive control. Cheese samples were ripened at 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 6 and 12 weeks of storage. All these treatments were compared with a cheddar cheese without vitamin E, selenium and ripened at 4 °C or 12 weeks. Vacuum packaged cheddar cheese was ripened 18 °C for a period of 12 weeks and analyzed for chemical and oxidative stability characteristics at 0, 4 and 8 weeks of storage period. RESULTS: Addition of Vitamin E and selenium did not have any effect on moisture, fat and protein content of cheddar cheese. After 6 weeks of ripening, total antioxidant capacity of T1, T2, T3, T4, T5, T6, T7 and standard cheese were 29.61%, 44.7%, 53.6%, 42.5%, 41.4%, 64.1%, 85.1% and 25.4%. After 6 weeks of ripening, reducing power of T1, T2, T3, T4, T5, T6, T7 and SC cheese were 14.7%, 18.1%, 26.3%, 19.2%, 25.3%, 33.4%, 40.3% and 11.6%. After 6 weeks of ripening, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of T6 and T7 were 54.2% and 66.9%. While, DPPH free radical scavenging activity of T1 and standard cheese after 6 weeks of ripening were, 19.1 and 18.5%, respectively. Free fatty acids of vitamin E and selenium supplemented, non-supplemented and standard cheese were not significantly influenced from each other in 0, 6 and 12 weeks old cheddar cheese. Peroxide values of T1, T2, T3, T4, T5, T6, T7 and standard cheese after 6 weeks of accelerated ripening were 1.19, 1.05, 0.88, 1.25, 0.29, 0.25, 0.24 and 0.28 (MeqO2/kg). After 6 weeks of ripening, anisidine value of T6 and T7 were 6.55 and 6.14. Conjugated dienes of T1, T2, T3, T4, T5, T6, T7 and standard cheese, after 6 weeks of accelerated ripening were 0.61, 0.55, 0.42, 0.77, 0.65, 0.17, 0.15 and 0.19. After 6 weeks of accelerated ripening, concentrations unsaturated fatty acids in T1, T2, T3, T4, T5, T6, T7 and standard cheese decreased by18.19%, 17.45%, 16.82%, 16.19%, 12.71%, 8.48%, 6.92% and 14.71%. After 12 weeks of accelerated ripening, concentration of unsaturated fatty acids in T1, T2, T3, T4, T5, T6 and T7 and standard cheese decreased by 26.2%, 21.2%, 18.7%, 14.2%, 10.4%, 4.84%, 1.03% and 6.78%. Cheddar cheese samples added with vitamin E, selenium and their combinations produced more organic acids during the ripening period of 12 weeks. After 6 and 12 weeks of ripening, flavor score of T6 and T7 was better than standard ripened cheddar cheese. CONCLUSIONS: After 6 weeks of accelerated ripening, sensory characteristics of T6 and T7 were similar to cheddar cheese that was ripened at 4 °C for 9 months. Ripening time of cheddar cheese may be reduced to 6 weeks by elevated temperature (18 °C) using vitamin E and selenium as antioxidants at T6 and T7 levels.

Impact of immediate and delayed chilling of raw milk on chemical changes in lipid fraction of pasteurized milk.

BACKGROUND: In many developing countries, milk chilling facilities are not available on the farm where milk is produced, rather these are located at the distance of 10-12 km. After milking, it takes about 2-3 h to reach milk to the chilling facilities. The milk is then chilled and transported to the milk processing plants for thermal processing and value addition. In developing countries, shelf life of pasteurized milk is only 3 days, as compared to 7-10 days in developed countries. The factors which are responsible for the shorter shelf life of pasteurized milk should be discovered for the improvement of dairy sectors of these countries. The magnitude of chemical changes which takes place in un-chilled milk and their effect on fatty acids profile, antioxidant status and lipid oxidation is not previously studied. METHODS: Raw milk samples of the same farm were either rapidly chilled to 4 °C immediately or held at room temperature (35 ± 2 °C) for 2 h followed by rapid chilling to 4 °C. Immediately and delayed chilled raw milk samples were stored at 4 °C for 72 h. Both milk samples were pasteurized at 65 °C, filled in 250 ml transparent PET bottles and stored at 4 °C for 6 days. Fatty acid profile, selenium, zinc, total antioxidant capacity, total flavonoid content and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, free fatty acids, peroxide value and anisidine value were determined at different stages of the experiment. This experiment was repeated with milk of same farm for at least five times. RESULTS: Storing raw milk at ambient temperature (35 ± 2 °C) significantly influenced the pH and lactose content of milk. The loss of short-chain fatty acids in delayed chilled milk was 1.19%, 3.27% and 1.60%, as compared to immediately chilled raw milk. In delayed chilled milk, loss of C18:1 and C18:2 after 3 days of storage period was 6.67% and 01.22. In delayed chilled milk after 6 days of storage, loss of C18:1 and C18:2 was 7.7% and 1.39%, respectively. In immediately chilled milk loss of C18:1 and C18:2 after 3 days of storage was 3.48% and 0.64%. In immediately chilled milk loss of C18:1 and C18:2 after 6 days of storage was 4.57% and 0.9%. Almost 41% vitamin E was lost when raw milk was stored at ambient temperature for 2 hrs. About 21% and 7% vitamin E was lost in delayed and immediately chilled milk, when samples were analyzed immediately after pasteurization. Loss of selenium and zinc contents after 2 h of ambient storage of raw milk were 0.43 and 224 µg/100 g. After 2 h of storage of milk at ambient temperature, free fatty acids increased by 0.03% (p < 0.05). After 6 days of storage, rise of free fatty acids in immediately and delayed chilled milk was 0.06% and 0.14%, respecitively. Rise of 0.13(MeqO2/kg) was recorded, when un-chilled raw milk was stored at ambient temperature for 2 h. After 3 and 6 days of storage, peroxide value of pasteurized milk (delayed chilled) was 0.88 and 1.56 (MeqO2/kg). After 3 and 6 days of storage, peroxide value of pasteurized (immediately chilled) was 0.39 and 0.42(MeqO2/kg). After 2 hrs of ambient storage, 18.41% flavonoids were lost. After 2 hrs of ambient storage of raw milk, loss of total antioxidant capacity and DPPH free radical scavenging activity was 29.31% and 44.53%. After 6 days of pasteurization, loss of total antioxidant capacity and DPPH free radical scavenging activity in delayed chilled raw milk was 72.1% and 89.57%. CONCLUSIONS: The findings of this investigation showed that delayed chilling of raw milk leads to several undesirable chemical changes in lipid fraction of milk.

Fatty Acid Composition, Phenolic Compounds, Phytosterols, and Lipid Oxidation of Single- and Double-Fractionated Olein of Safflower Oil Produced by Low-Temperature Crystallization.

By dry crystallization, concentrations of unsaturated fatty acids and bioactive compounds can be increased in olein and super-olein fractions in vegetable oils. Among all sources of vegetable oils, safflower oil (SO) possesses the maximum linoleic acid content. To boost the industrial applications of SO, two variants were produced by single- and two-stage crystallization. This study aimed to determine the fatty acid compositions, phenolic compounds, phytosterols, and oxidative stability of fractionated olein (OF) and double-fractionated olein (DFO) produced by dry crystallization. For this, SO was cooled to -45 °C and filtered, the filtrate was denoted as single-fractionated olein (OF), and 40% of this section was taken for analytical purposes, while the remaining 60% was again cooled to -70 °C and filtered, and the filtrate was denoted as double-fractionated olein (DFO). Unfractionated safflower (SO) was used as a control, filled in amber glass bottles, and stored at 20-25 °C for 90 days. Fatty acid compositions and phytosterols were determined by gas chromatography-mass spectrometry (GC-MS). Phenolic compounds and induction periods were determined by high-performance liquid chromatography (HPLC) and Rancimat. GC-MS analysis revealed that the C18:2 contents of SO, OF, and DFO were 77.63 ± 0.82, 81.57 ± 0.44, and 89.26 ± 0.48 mg/100 g (p < 0.05), respectively. The C18:1 contents of SO, OF, and DFO were 6.38 ± 0.19, 7.36 ± 0.24, and 9.74 ± 0.32 mg/100 g (p < 0.05), respectively. HPLC analysis showed that phenolic compounds were concentrated in the low-melting-point fractions. In DFO, concentrations of tyrosol, rutin, vanillin, ferulic acid, and sinapic acid were 57.36 ± 0.12, 129.45 ± 0.38, 165.11 ± 0.55, 183.61 ± 0.15, 65.94 ± 0.11, and 221.75 ± 0.29 mg/100 g, respectively. In SO, concentrations of tyrosol, rutin, vanillin, ferulic acid, and sinapic acid were 24.79 ± 0.08, 78.93 ± 0.25, 115.67 ± 0.41, 34.89 ± 0.51, and 137.26 ± 0.08 mg/100 g, respectively. In OF, concentrations of tyrosol, rutin, vanillin, ferulic acid, and sinapic acid were 35.96 ± 0.20, 98.69 ± 0.64, 149.14 ± 0.13, 57.53 ± 0.74, and 188.28 ± 0.82 mg/100 g, respectively. The highest concentrations of brassicasterol, campesterol, stigmasterol, ß-sitosterol, avenasterol, stigmastenol, and avenasterol were noted in DFO followed by OF and SO. The total antioxidant capacities of SO, OF, and DFO were 54.78 ± 0.12, 71.36 ± 0.58, and 86.44 ± 0.28%, respectively. After the end of the storage time, the peroxide values (POVs) of SO, OF, and DFO stored for 3 months were 0.68, 0.85, and 1.16 mequiv O2/kg, respectively, with no difference in the free fatty acid content.

Descriptive Sensory Analysis of Pizza Cheese Made from Mozzarella and Semi-Ripened Cheddar Cheese Under Microwave and Conventional Cooking.

The present study used descriptive sensory analysis (DSA) to compare Pizza cheeses prepared from various combinations of fresh Mozzarella and semi-ripened Cheddar cheeses and cooked under conventional and microwave cooking methods. A cheese sensory lexicon was developed, and descriptive sensory profiles of the Pizza cheeses were evaluated using a panel of semi-trained judges (n = 12). The following characteristics, flavor (cheddar, acidic, rancid, bitter, salty, creamy, and moldy), texture (stringiness, stretchability, firmness, and tooth pull), and appearance (meltability, oiliness, edge browning, and surface rupture) of Pizza cheeses were analyzed and compared with control samples. The sensory analysis of Pizza cheeses showed more preference toward a higher level of ripened Cheddar cheese (4 months), which was cooked using the microwave. However, the scores for texture properties were decreased with the addition of the semi-ripened cheese. The scores for stretchability and tooth pull were high in the microwave cooked samples compared with the conventionally cooked samples. The appearance attributes (meltability, oiliness, and edge browning) scores were increased with the increasing of ripened Cheddar cheese content while surface rupture was decreased. Microwave cooked Pizza cheese showed better meltability and oiliness but lower edge browning scores. The results showed that amalgamations of fresh Mozzarella and semi-ripened Cheddar cheese had a significant (p < 0.05) and positive effects on the sensory qualities of Pizza cheeses.