Improving the storage and oxidative stability of essential fatty acids by different encapsulation methods; a review.

Linoleic acid and α-linolenic acid are the only essential fatty acids (EFAs) known to the human body. Other fatty acids (FAs) of the omega-6 and omega-3 families originate from linoleic acid and α-linolenic acid, respectively, by the biological processes of elongation and desaturation. In diets with low fish consumption or vegetarianism, these FAs play an exclusive role in providing two crucial FAs for maintaining our body's vital functions; docosahexaenoic acid and arachidonic acid. However, these polyunsaturated FAs are inherently sensitive to oxidation, thereby adversely affecting the storage stability of oils containing them. In this study, we reviewed encapsulation as one of the promising solutions to increase the stability of EFAs. Accordingly, five main encapsulation techniques could be classified: (i) spray drying, (ii) freeze drying, (iii) emulsification, (iv) liposomal entrapment, and (v) other methods, including electrospinning/spraying, complex coacervation, etc. Among these, spray drying was the frequently applied technique for encapsulation of EFAs, followed by freeze dryers. In addition, maltodextrin and gum Arabic were the main wall materials in carriers. Paying attention to industrial scalability and lower cost of the encapsulation process by the other methods are the important aspects that should be given more attention in the future.

Modulation of toxicity effects of CuSO4 by sulfated polysaccharides extracted from brown algae (Sargassum tenerrimum) in Danio rerio as a model.

Copper is widely used in agriculture and aquaculture due to its high disinfection properties and relatively low cost. However, the increase in copper concentration due to evaporation can lead to water reservoir pollution, which can harm the health of consumers. The present study aimed to determine the role of sulfated polysaccharides (SPs) extracted from Sargassum tenerimum algae in reducing lesions caused by the heavy metal copper. Zebrafish (Danio rerio) were used as a human model in five treatments. The negative and positive control groups were fed a diet containing zero percent of SPs, while the experimental groups were fed 0.5%, 1%, and 1.5% of SPs in three treatments for 56 days, finally CuSO4 was exposed only to the positive control group and the groups fed with SPs. Results showed a significant decrease in the activity level of ALT enzymes (39-16 U/mL), AST (67-46 U/mL), and ALP (485-237 U/mL), confirming the results obtained from histopathological studies in CuSO4 exposed groups. The addition of SPs to the diet resulted in a significant reduction (sig < 0.05) of mortalities due to the decrease of tissue damage. Additionally, due to the anti-inflammatory properties and the protective effect of SPs, a significant decrease (sig < 0.05) was observed in the relative expression of Il-1ß and Tnf-α genes.

Improving the thermal stability of natural bioactive ingredients via encapsulation technology.

Bioactive compounds (bioactives) such as phenolic acids, coumarins, flavonoids, lignans and carotenoids have a marked improvement effect on human health by acting on body tissues or cells. Nowadays, with increasing levels of knowledge, consumers prefer foods that can provide bioactives beside the necessary nutrients (e.g., vitamins, essential fatty acids and minerals). However, an important barrier for incorporating bioactives into foods is their low thermal stability. Nevertheless, thermal processing is widely used by the food industries to achieve food safety and desired texture. The aim of this work is to give an overview of encapsulation technology to improve thermal stability of bioactives incorporated into different food products. Almost all thermal analysis and non-thermal methods in the literature suggest that incorporation of bioactives into different walls can effectively improve the thermal stability of bioactives. The level of such thermal enhancement depends on the strength of the bioactive interaction and wall molecules. Furthermore, contradictory results have been reported in relation to the effect of encapsulation technique using the same wall on thermal stability of bioactives. To date, the potential to increase the thermal resistance of various bioactives by gums, carbohydrates, and proteins have been extensively studied. However, further studies on the comparison of walls and encapsulation methods to form thermally stable carriers seem to be needed. In this regard, the same nature of bioactives and the specific protocol in the report of study results should be considered to compare the data and select the optimum conditions of encapsulation to achieve maximum thermal stability.

Practical application of nanoencapsulated nutraceuticals in real food products; a systematic review.

In recent decades, due to the increase in awareness, most consumers prefer foods that not only satisfy their primal urge of hunger but also include health-promoting effects on the body. Therefore, the food industry has an increasing tendency to apply the nutrients (like vitamins, essential fatty acids and minerals) and replace synthetic additives with natural bioactives (like phenolics and essential oils) to produce functional products. However, low dispersibility and shelf-stability as well as presenting unpleasant taste and odor are the most critical barriers for direct incorporation of these useful compounds into foods. In this context, nanoencapsulation has been proposed as a relatively new solution to overcome the mentioned limitations. However, fewer studies have focused on incorporating the bioactive-loaded nanocarriers into the food matrices. This study intends to help the development of functional food production by doing an exhaustive review on the incorporation of nanoencapsulated ingredients into the real food system and resulted interaction of nanocarriers and food products. According to the literature, incorporation of the nanoencapsulated bioactive ingredients into foods can be effectively used to enhance their stability during the processing and storage stage and their bioavailability as well as to delay lipid oxidation and microbial growth in food, without negatively affecting physicochemical, organoleptic and qualitative properties. However, some published results to date declared that food matrix might adversely affect the bioavailability and antimicrobial activity of nanoencapsulated ingredients. It seems that further studies are required to contribute to the choice of appropriate healthy ingredients and wall materials for incorporating into a given food structure.

A comprehensive review on the nanocomposites loaded with chitosan nanoparticles for food packaging.

Chitosan is mainly derived from seafood by-products and the thereof chitosan nanoparticles (CNPs) are known as nontoxic, biocompatible, biodegradable and functionalized nanostructures. CNPs, as green fillers, showed an appropriate potential in reinforcement of various biodegradable composites for food packaging and biomedical applications. After evaluation of different fabrication approaches and characterization techniques of CNPs, the changes in physical, mechanical, thermal, structural, morphological, and antimicrobial attributes of nanobiocomposites as a result of CNPs addition are discussed. The influence of bioactive loaded-CNPs and hybrid CNPs with metal nanoparticles, graphene, and montmorillonite in nanocomposites is also presented. Finally, the safety aspects of CNPs-loaded structures are highlighted to evaluate their implementation in food packaging and biomedical systems. It can be concluded that regardless of a few drawbacks, CNPs are promising nanomaterials to improve various operational, structural and antimicrobial properties of biocomposites for various applications in food packaging, delivery systems and biomedical uses.

Gum Tragacanth: Structure, characteristics and applications in foods.

Due to the high demand (consumers and regulatory authorities) on elimination or reduction of 'additives' in food and other health related products, there is increasing interest on natural macromolecules or hydrocolloids such as gums. Gum Tragacanth (GT) is a multifunctional exudate gum with unique thickening, emulsifying, viscosity improving, stabilizing, gelling and structuring capabilities. Owing to its distinctive functionality, it has been extensively used in low-fat or non-fat food formulations, colloid-based products, edible films and coatings and (nano) encapsulation of food ingredients. This review provides the comprehensive information on its physicochemical, structural and functional characteristics with a particular focus on its application in foods.

The effect of gelatin and thymol-loaded nanostructured lipid carrier on physicochemical, rheological, and sensory properties of sesame paste/date syrup blends as a snack bar.

The development of a novel snack bar based on sesame paste (SP) and date syrup (DS) was investigated. The aim of this study was to evaluation the effects of SP/DS ratio and encapsulated thymol (thymol-loaded nanostructured lipid carrier [TNLC]) on physicochemical, textural, rheological, and sensorial properties of snack bars. The effect of butylated hydroxytoluene (BHT), thymol, and TNLC showed that the addition of 100 ppm TNLC could improve the oxidative stability of SP/DS mixtures even better than BHT, while a higher concentration of TNLC had a negative effect. The unpleasant taste and odor of thymol could be overcome by its encapsulation in nanostructured lipid carriers. The textural properties of the formulations with different SP/DS ratios (1:2, 1:1, 2:1) and an overall concentration of 7 g of gelatin/kg of mixtures were evaluated. The texture profile analysis showed that the sample with an SP/DS ratio of 1:1 had higher hardness, adhesiveness, springiness, cohesiveness, and gumminess in comparison with the other ratios. From the sensory evaluation data, the bar prepared with an SP/DS ratio of 1:1 had the most acceptable texture. According to the results, the SP/DS ratio of 1:1 with gelatin and 100 ppm TNLC can be used in developing SP/DS blends as a highly acceptable functional food.

Using the mixture design approach to predict the rheological properties of low-calorie dairy desserts containing gum tragacanth exuded by three Iranian Astragalus species.

In this study, the flow behavior and creep parameters of saffron desserts containing gum tragacanth combinations of three species were modeled by the mixture design approach. Flow behavior and creep-recovery experiments were performed and models were predicted for apparent viscosity, consistency index, flow index, instantaneous compliance, and viscoelastic compliance. Five representative samples regarding the range of apparent viscosity at the shear rate of 50 s-1 were subjected to sensory evaluation. According to rheological measurements, the addition of GT species of A. gossypinus led to the production of a dessert with a strong structure. Then, two samples with the highest consistency index and the lowest creep parameters were compared with two commercial saffron desserts. The results revealed that the overall acceptance of the two selected samples [containing 4% (w/w) A. gossypinus or 2.66% (w/w) A. gossypinus and 1.33% (w/w) A. fluccosus] was similar to those of the two commercial samples.

Formation of concentrated triglyceride nanoemulsions and nanogels: natural emulsifiers and high power ultrasound.

The fabrication of concentrated nanoemulsions provides potential advantages such as loading capacity enhancement, storage and transportation costs reduction, and creation of novel textures. The current study investigated the capability of high power ultrasound on nanoemulsification of high concentration triglyceride using various natural emulsifiers (saponin, whey protein isolate, lecithin and sucrose monopalmitate). The impact of the emulsifier concentration (up to 6 wt%), oil content (up to 60 wt%) and exposure to sonication (up to 33 min) on the droplet size distribution, physical stability and rheological properties were evaluated. Regarding the dilute nanoemulsion (10 wt% oil), droplet size was inversely correlated with the concentration of emulsifiers, however only by using saponin (2 wt%) the droplet size was in nano range (d < 200 nm). The concentrated nanoemulsions (20-50 wt%) were also fabricated under sonication (15 min at saponin-to-oil ratio 2 : 10 w/w%). They also presented shear-thinning behavior with relatively low consistency coefficients. Surprisingly, the one with 60 wt% oil was easily converted to viscoelastic gel upon 3 min sonication. Owing to such characteristics, they could have potential applicability in formulation of soft foods, creams, sauces, salad dressings, pastes, lotions, cosmetics and pharmaceuticals.

Application of different nanocarriers for encapsulation of curcumin.

Curcumin is the main polyphenol of the curcuminoid class of turmeric, a well-known spice belonging to the ginger family. In addition to its common applications like coloring and antioxidant agent as food additives, it has a broad range of favorable biological functions, such as anti-inflammatory, anti-microbial, anti-diabetic activities, and anti-cancer potentials against various cancers. However, curcumin suffers from some limitations including short shelf life due to its poor chemical stability, low bioavailability due to its poor absorption, low water solubility, rapid metabolism and rapid systemic elimination. Nanoencapsulaion has been addressed as an innovative and emerging technology for resolving these shortcomings. In this review, the different delivery systems used for loading of curcumin have been considered and explained including lipid-based, chemical polymer and biopolymer-based, nature-inspired, special equipment-based and surfactant-based techniques. Also, implications of nanoencapsulated curcumin in food, pharmaceutical and cosmetic uses are discussed. In this sense, the relevant recent studies in the past few years along with upcoming challenges have been covered. Although incorporation of curcumin into nanocarriers can be a possible solution to overcome its inherent constraints, there are some rational concerns about their toxicological safety once they enter into the biological paths. Therefore, future investigations could focus on assessment of their biological fate during digestion and absorption within human body.

Ultrasonic-Assisted Fabrication of Concentrated Triglyceride Nanoemulsions and Nanogels.

In many food products such as gels, pastes, jellies, creams, sausages, and selected dressings or spreads, it is desirable to formulate concentrated triglyceride nanoemulsions so as to deliver lipophilic functional agents. In this study, the ability of ultrasonication to form nanoemulsions and nanogels containing high concentration of sunflower oil was investigated in the presence of sodium dodecyl sulfate (SDS) as a surfactant. The influence of SDS and oil concentration and duration of sonication on the physical stability, mean droplet diameter, and rheological properties of emulsions were determined. Ultrasonication for up to 9 min was highly effective on fabrication of stable nanoemulsions (an average droplet size of 158-171 nm) at low oil/surfactant ratio (10:0.7). The viscosity and storage modulus increased with decreasing the droplet size particularly at higher oil concentrations. The viscous nanoemulsions (containing 60, 50, and 40 wt % oil) transformed into viscoelastic gels when sonicated for 3, 9, and 30 min, respectively. On the basis of the findings of the present study, such textural and rheological modifications, resulted from droplet size decreasing, could be potentially useful in designing reduced fat gel-like products.

Formulation and pilot scale production of low-trans vanaspati with modified polyunsaturated fatty acids content.

Pilot scale production of low-trans vanaspati through a combination of techniques including non-selective hydrogenation of palmolein and physical blending of 3 vegetable oils, namely Canola, soybean and sunflower oils was investigated. Six formulations (A-F) of trans-free vanaspati were prepared. The fatty acid composition, peroxide value, acid value, iodine value, slip melting point (SMP), solid fat content (SFC) at 10-40 °C and oil/oxidative stability of the formulations were evaluated. The percentage of trans-fatty acids obtained for vanaspati formulations were within the value recommended by WHO (<4), except for B and D formulations (5.81 and 5.28, respectively). A and E formulations had the lowest trans-fatty acids content. The total saturated fatty acids (SFA) in the vanaspati formulations ranged from 22.96 to 30.11 %. Among the six formulations, A showed the significant percentage of SFA. The highest and the Lowest of linolenic acid contents were obtained for samples E (4.36 %) and F (0.28 %). Percentage of the monounsaturated fatty acids (MUFA) of the vanaspati formulations suggested an order from the highest to lowest as: A > C > E > F > D > B formulations. B formulation had the highest significant percentage of PUFA, followed by D, E, F, C, and A formulations. Only A vanaspati had the induction periods (IP) of higher than commercial low-trans vanaspati, while the lowest stability time belonged to sample B (10.20 h). SMP of all the vanaspati formulations was higher than the commercial low-trans vanaspati, but less than 40 °C. Although A and E formulations contained lower SFA than the commercial low-trans vanaspati, they indicated higher SFC at 20-40 °C. According to the above information, E and A formulations could be recommended as suitable formulations for further research in a larger scale.

Milk protein-gum tragacanth mixed gels: effect of heat-treatment sequence.

The aim of this study was to investigate the role of the heat-treatment sequence of biopolymer mixtures as a formulation parameter on the acid-induced gelation of tri-polymeric systems composed of sodium caseinate (Na-caseinate), whey protein concentrate (WPC), and gum tragacanth (GT). This was studied by applying four sequences of heat treatment: (A) co-heating all three biopolymers; (B) heating the milk-protein dispersion and the GT dispersion separately; (C) heating the dispersion containing Na-caseinate and GT together and heating whey protein alone; and (D) co-heating whey protein with GT and heating Na-caseinate alone. According to small-deformation rheological measurements, the strength of the mixed-gel network decreased in the order: C>B>D>A samples. SEM micrographs show that the network of sample C is much more homogenous, coarse and dense than sample A, while the networks of samples B and D are of intermediate density. The heat-treatment sequence of the biopolymer mixtures as a formulation parameter thus offers an opportunity to control the microstructure and rheological properties of mixed gels.

Evaluation of Anticancer Activity of Fruit and Leave Extracts from Virus Infected and Healthy Cultivars of Vitis vinifera.

OBJECTIVE: Grape virus diseases are a serious problem in Iran. Leaves and fruits of grape have been used for different purposes like cooking in Iran. The present investigation was carried out to study on the cytotoxic-activities of extracts of fruits and leaves of Vitis vinifera from both virus-free and virus-infected grape cultivars against breast cancer cell line (MDAMB- 231) and human embryonic kidney normal cell line (HEK 293). MATERIALS AND METHODS: IN THIS EXPERIMENTAL STUDY, THE CONSIDERED GRAPE CULTIVARS WERE AS FOLLOWS: Rish Baba Sefid, Shahani Ghasre Shirin, Rotabi Zarghan, Asgari Najaf Abad, Fars, Kaj Angor Bojnord, Sarkesh Shiraz and Siahe Zarqan. A real-time multiplex polymerase chain reaction (real-time Multiplex PCR) assay was applied to detect virus infected cultivars. The cytotoxic effect of the methanol extracts of different Vitis vinifera varieties on cultured cells was monitored using (3- (4, 5-Dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide (MTT) assay at different concentrations (62.5, 125, 250, 500, 750, 1000 µg mL(-1)). RESULTS: Among these cultivars, Grapevine fanleaf virus (GFLV) along with related symptoms was detected in Siahe Zarqan and Fars. Methanolic extracts of leaves and fruits of Vitis vinifera from both virus free and virus infected cultivars showed a range of limited to moderate cytotoxic activity. However, methanol extract of leaves belonged to virus infected cultivars was found to have strong cytotoxic effect against MDA-MB-231 at different concentrations. CONCLUSION: Grapevine fanleaf virus (GFLV) can potentially increase the cytotoxicity of grape cultivars.

Effect of gum tragacanth exuded by three Iranian Astragalus on mixed milk protein system during acid gelation.

The effects of various concentrations of three species of gum tragacanth on the gelation process, microstructure and viscoelastic properties of milk protein mixed gels acidified at 37°C by glucono-δ-lactone (GDL) were investigated using dynamic rheometry and microscopy. According to rheological measurements, the addition of gum tragacanth in the range of 0.05-0.2% (w/w) into milk protein dispersions led to a weaker structure for the milk protein network, compared to the control sample. This weakening effect could be eliminated by adding 0.3% (w/w) gum tragacanth exudates from A. gossypinus; the compositional features of gum tragacanth may have been responsible for the improved protein-protein interactions, greater structural strength and reduced gelation time onset. It was determined by scanning electron microscopy that the addition of gum tragacanth at a low concentration caused the density of the matrix to increase, while an open structure was observed in the presence of a higher gum concentration.

Effect of co-solute and gelation temperature on milk protein and gum tragacanth interaction in acidified gels.

The aim of this study was to investigate the role of process conditions and system composition on the acid-induced gelation of a mixture of milk protein and gum tragacanth. This was studied by determining the effects of co-solute (lactose) addition (3, 5 and 7%) and gelation temperature (25, 37 and 45°C) on the mixture's rheological properties and microstructure using a combination of techniques including small-deformation rheology and scanning electron microscopy. The presence of lactose played an important role in the microstructure formation of gels but did not change most rheological properties. The microstructure of gels formed in the presence of lactose was coarser and more particulate, but less interconnected; this can be explained by lactose's role in improving protein aggregation. Gels prepared at a lower temperature had a high structure strength, as indicated by their high storage modulus, τ(f) and G(f) values. Low gelation temperature also caused a more branched and homogenous microstructure.