Recent advances in iron encapsulation and its application in food fortification.

Iron (Fe) is an important element for our body since it takes part in a huge variety of metabolic processes. However, the direct incorporation of Fe into food fortification causes a number of problems along with undesirable organoleptic properties. Thus, encapsulation has been suggested to alleviate this problem. This study first sheds more light on the Fe encapsulation strategies and comprehensively explains the results of Fe encapsulation studies in the last decade. Then, the latest attempts to use Fe (in free or encapsulated forms) to fortify foods such as bakery products, dairy products, rice, lipid-containing foods, salt, fruit/vegetable-based products, and infant formula are presented. Double emulsions are highly effective at keeping their Fe content and display encapsulation efficiency (EE) > 88% although it decreases upon storage. The encapsulation by gel beads possesses several advantages including high EE, as well as reduced and great Fe release in gastric and duodenal conditions, respectively. Cereals, particularly bread and wheat, are common staple foods globally; they are very suitable for food fortification by Fe derivatives. Nevertheless, the majority of Fe in flour is available as salts of phytic acid (IP6) and phytates, reducing Fe bioavailability in the human body. The sourdough process degrades IP6 completely while Chorleywood Bread Making Process and conventional processes decrease it by 75% in comparison with whole meal flour.

Extraction and purification of α-pinene; a comprehensive review.

Extensive use of α-pinene in cosmetics, and medicine, especially for its antioxidant/antibacterial, and anti-cancer properties, and also as a flavoring agent, has made it a versatile product. α-Pinene (one of the two pinene isomers) is the most abundant terpene in nature. When extracting α-pinene from plants and, to a lesser extent, fruits, given that its purity is essential, purification methods should also be used as described in this study. Also, an attempt has been made to describe the extraction techniques of α-pinene, carried out by conventional and novel methods. Some disadvantages of conventional methods (such as hydrodistillation or solvent extraction) are being time consuming, low capacity per batch and being labor intensive and the requirement of trained operators. Most novel methods, such as supercritical fluid extraction and microwave-assisted extraction, can reduce the extraction time, cost, and energy compared to conventional methods, and, in fact, the extraction and preservation efficiency of α-pinene in these methods is higher than conventional methods. Although the above-mentioned extraction methods are effective, they still require rather long extraction times. In fact, advanced methods such as green and solvent-free ultrasonic-microwave-assisted extraction are much more efficient than microwave-assisted extraction and ultrasound-assisted extraction because the extraction efficiency and separation of α-pinene in these methods are higher; furthermore, no solvent consumption and maximum extraction efficiency are some crucial advantages of these techniques. However, the application of some novel methods, such as ultrasound-assisted extraction, in industry scale is still problematic because of their intricate design data.

Nano-vesicular carriers for bioactive compounds and their applications in food formulations.

The most commonly used vesicular systems in the food industry include liposomes, niosomes, phytosomes, or transfersomes. This review focuses on showing how nano-vesicular carriers (NVCs) amend the properties of bioactive compounds (bioactives), making them suitable for food applications, especially functional foods. In this research, we elaborate on the question of whether bioactive-loaded NVCs affect various food aspects such as their antioxidant capacity, or sensory properties. This review also shows how NVCs improve the long-term release profile of bioactives during storage and at different pH values. Besides, the refinement of digestibility and bioaccessibility of diverse bioactives through NVCs in the gastrointestinal tract is elucidated. NVCs allow for stable vesicle formation (e.g. from anthocyanins) which reduces their cytotoxicity and proliferation of cancer cells, prolongs the release bioactives (e.g. d-limonene) with no critical burst, reduces the biofilm formation capacity of both Gram-positive/negative strains and their biofilm gene expression is down-regulated (in the case of tannic acid), low oxidation (e.g. iron) is endured when exposed to simulated gastric fluid, and unpleasant smell and taste are masked (in case of omega-3 fatty acids). After the incorporation of bioactive-loaded NVCs into food products, their antioxidant capacity is enhanced, maintaining high encapsulation efficiency and enduring pasteurization conditions, and they are not distinguished from control samples in sensory evaluation despite the reverse situation about free bioactives.

Effect of Different Drying Methods on the Physicochemical Properties and Bioactive Components of Saffron Powder.

Saffron is the most expensive spice in the world; so, determining optimum conditions for its processing is crucial. The most important processing stage of saffron is drying of its stigma, which should be optimized and there are no reports on reactance-window (RW) of saffron. In this research, drying of saffron with traditional, RW, and oven driers and at three temperatures of 60, 70 and 80 °C, as well as room temperature (25 °C) were studied. Regarding process duration, RW drier with 200 µm Mylar membrane and oven drier were the best methods with average drying time of 25.28 and 22.28 min, respectively. As far as the concentration of bioactive ingredients, i.e., picrocrocin, safranal, and crocin, of saffron was concerned, RW drier with Pyrex glass was better than other driers, resulting in 112.83 [Formula: see text] of picrocrocin, 51.79 [Formula: see text] of safranal, and 274.76 [Formula: see text] of crocin. The panelist most favored those saffron samples dried by RW with 300 µm Mylar membrane.

Arrhenius equation modeling for the shelf life prediction of tomato paste containing a natural preservative.

BACKGROUND: The shelf life of tomato paste with microencapsulated olive leaf extract was compared with that of samples containing a commercial preservative by accelerated shelf life testing. Based on previous studies showing that olive leaf extract as a rich source of phenolic compounds can have antimicrobial properties, application of its encapsulated form to improve the storage stability of tomato paste is proposed here. RESULTS: Regarding total soluble solids, the control and the sample containing 1000 µg g-1 sodium benzoate had the lowest (Q10 = 1.63) and highest (Q10 = 1.88) sensitivity to temperature changes respectively; also, the microencapsulated sample containing 1000 µg g-1 encapsulated olive leaf extract (Q10 = 1.83) followed the sample containing 1000 µg g-1 sodium benzoate in terms of the highest kinetic rates. In the case of consistency, the lowest and highest activation energies (Ea ) corresponded to samples containing 1000 µg g-1 non-encapsulated olive leaf extract and 1000 µg g-1 microencapsulated olive leaf extract respectively. CONCLUSION: Interestingly, samples containing microencapsulated olive leaf extract could maintain the original quality of the tomato paste very well, while those with non-encapsulated olive leaf extract rated the worst performance (among all specimens) in terms of maintaining their quality indices for a long time period. Overall, the shelf life equation was able to predict the consistency index of all tomato paste samples during long-time storage with high precision. © 2017 Society of Chemical Industry.

Production of soft unripened cheeses using acidic and salty coagulants: Investigation of technological and sensory characteristics.

Soft cheeses are coagulated milk products obtained through acidification or applying a combination of acids and heat. In this research, in order to improve technological characteristics, the effects of different coagulants (salt and acids) and process parameters (temperature and homogenization pressure) on the organoleptic, textural, and functional characteristics of soft (unripened) cheese were investigated. The results revealed significant differences between cheeses coagulated with acid and mineral salt regarding protein recovery, fat content, and moisture content (p < .05). Acidic coagulants (74%-94%) resulted in higher cheese yield compared to mineral salt (66%-88%). Texture analysis indicated that the cheese produced with acetic acid had a firmer texture, while samples treated with citric acid exhibited better cohesiveness. Cheeses produced with minerals displayed more acceptable organoleptic characteristics regarding flavor, odor, and texture. This study offers valuable technological insights into cheese production with the highest yield and maximum acceptability.

Improving the storage stability of tomato paste by the addition of encapsulated olive leaf phenolics and experimental growth modeling of A. flavus.

It is necessary to apply some preservatives for tomato paste since in the harvest season, a high load of tomatoes need to be processed as they are among highly perishable products. Application of antimicrobial extracts or essential oils, as natural preservatives, in their raw forms might reduce their efficiency when they are exposed to environmental conditions. However, microencapsulation is a well-known method to solve this problem. Our main goal was to restrict fungal growth rate in stored tomato paste and increase its storage stability by incorporating encapsulated olive leaf phenolic-rich extract. Total Soluble Solids (TSS), consistency, pH, color indices and diametrical growth rate of Aspergillus flavus were measured for different samples. The treatments designed in terms of considering two levels of non-encapsulated olive phenolics extract with 500 and 1000 ppm (NE500 and NE1000), the same levels with encapsulated extract; i.e., 500 and 1000 ppm (ME500 and ME1000), and similar levels of the common preservative of sodium benzoate with 500 and 1000 ppm (B500 and B1000). Antifungal properties of NE samples were higher than ME ones during storage although ME samples could maintain diametrical growth rate of the fungus more stable than NE ones. NE samples justified lower maximum growth rate than ME samples while ME samples could extend lag phase of microbial growth compared with NE one and delay their internal deteriorative reactions. Among Baranyi, modified Baranyi, Modified Gompertz, and Logistic models, Modified Gompertz model represented the best model and could fit the growth factors of A. flavus on tomato paste with higher R2 index as well as lower RMSE and SSE indices. Based on the results obtained, it could be concluded that usage of encapsulated olive leaf extract in tomato paste is an effective, natural and sustainable approach to improve the shelf life of tomato paste since this natural compound could perform as favourable as preservatives; also it could maintain physicochemical as well as microbial properties of tomato paste for a long term. Thus, it is strongly recommended that application of encapsulated olive leaf extract to be considered seriously by the tomato paste industry as it can effectively reduce the mold and fungal contaminations which are very common and prevalent in the plants. The future work in this regard should focus on sensory evaluations when incorporating encapsulated olive leaf extract into tomato paste.

The influence of nanocellulose coating on saffron quality during storage.

Since saffron is an added-value product, and the most expensive agricultural product, it is necessary to increase its shelf life, prevent its quality loss during storage, and maintain its organoleptic properties, enabling producers to export saffron with higher quality and better consumer acceptability. So, in this research, saffron samples were coated through applying different carbohydrate biopolymers: maltodextrin with DE=4 or DE=20 (MD4 and MD20) or their combination with nanocellulose fibres (MDC4 and MDC20). Finally, the experiments were carried out to measure rehydration ratio, water activity, crocin content, color values, and sensory properties of saffron samples coated by different materials. MDC4 resulted in the lowest rehydration ratio among coated samples since, first, lower DE degrees of biopolymer complexes decreased moisture adsorption and solubility of maltodextrin and second, crystalline nanocellulose fibres increased tortuous and bended pathways in materials and reduced penetration possibilities of water molecules. MDC4 was the most effective treatment in preventing crocin decrease. Indeed, film forming characteristic of maltodextrin with low hydrolysis degree and special structure of nanocellulose led to the maintenance of crocin bioactive ingredient. SEM observations revealed coating on saffron surfaces as a thin clear and brilliant layer which enhanced saffron acceptability for our panelists.

Preparation and characterization of nano-SiO2 reinforced gelatin-k-carrageenan biocomposites.

The main goal of this study was to prepare bionanocomposites by combination of gelatin (10% w/v), k-carrageenan (0.5%) and nano-SiO2 (1, 3 or 5%). Then, mechanical properties (tensile strength, elongation at break, Young's modulus), gas permeability (water vapor, oxygen), water solubility, color, UV-vis transmission/absorbance, water vapor adsorption isotherms and Fourier transform infrared (FTIR) analysis of nanocomposites were evaluated. As the results indicated, inclusion of nano-SiO2 (at each level) could increase tensile strength and Young's modulus significantly, with the latter becoming nearly 110% higher at 5% nanoparticle level compared with gelatin-carrageenan biocompostes. Furthermore, incorporation of 5% nano-SiO2 could decrease water vapor permeability of biocomposites from 8.9 to 1.6 × 10-11 g m-1 s-1 Pa-1 and their oxygen permeability from 226 to 97 cm3 µm m-2 day-1 atm-1. Water vapor adsorption isotherms revealed that the water activity of 0.5 was the critical point beyond which the difference in equilibrium moisture content between nanoparticle-incorporated films and biocomposites increased considerably. Besides, this research demonstrated that including 5% of nano-SiO2 is a good solution to delay UV light driven reactions as it elevated absorbance of UV light (220 nm) by biocomposites up to 4 times.

Microencapsulation optimization of natural anthocyanins with maltodextrin, gum Arabic and gelatin.

The barberry (Berberis vulgaris) extract which is a rich source of anthocyanins was used for spray drying encapsulation with three different wall materials, i.e., combination of maltodextrin and gum Arabic (MD+GA), maltodextrin and gelatin (MD+GE), and maltodextrin (MD). Response Surface Methodology (RSM) was applied for optimization of microencapsulation efficiency and physical properties of encapsulated powders considering wall material type as well as different ratios of core to wall materials as independent variables. Physical characteristics of spray-dried powders were investigated by further analyses of moisture content, hygroscopicity, degree of caking, solubility, bulk and absolute density, porosity, flowability and microstructural evaluation of encapsulated powders. Our results indicated that samples produced with MD+GA as wall materials represented the highest process efficiency and best powder quality; the optimum conditions of microencapsulation process for barberry anthocyanins were found to be the wall material content and anthocyanin load of 24.54% and 13.82%, respectively. Under such conditions, the microencapsulation efficiency (ME) of anthocyanins could be as high as 92.83%.

Hydrophobicity, thermal and micro-structural properties of whey protein concentrate-pullulan-beeswax films.

In this research, effects of beeswax (BW) on functional properties of whey protein concentrates (WPC):pullulan (PUL) films were investigated. For this purpose, 0, 10, 20 and 30w/w(glycerol)% BW rates and 30:70, 50:50 and 70:30w/w% WPC:PUL ratios were applied. Films containing 70% WPC:30% PUL (WPC70) and 30% BW (BW30) justified the highest contact angle (92.4°) among all films; SEM micrographs indicated that BW could come toward the surface of films during drying stage and resulted in a higher hydrophobic behavior of bilayer films compared with blend films. WPC70 supplied the lowest T(g) values (36-48 °C) among different proportions of WPC-PUL; the highest melting points were just assured in the absence of BW regardless of combination ratio for WPI:PUL. BW30 films deserved lower roughness rates than BW20 (and even BW10) films, indicating more advantageous microstructure and higher hydrogen connections in BW30 films and justifying similar melting points attained for BW30 films to BW20 or 10 ones. Overall, application of WPC70 and BW30 was recommended to obtain optimum combination of final properties for WPC-PUL-BW bilayer films as SEM exhibited flexible and elastic structures of such films.

Physical and mechanical properties in biodegradable films of whey protein concentrate-pullulan by application of beeswax.

Different ratios of whey protein concentrate (WPC):pullulan (PUL) (70:30, 50:50, 30:70%w/w) and various rates of beeswax (BW) (0, 10, 20, and 30%w/wglycerol) were applied to prepare biodegradable WPC-PUL films containing glycerol as a plasticizer, for the first time. Thickness, moisture content, water solubility, water vapour permeability, colour, and mechanical properties of prepared films were measured. Higher ratios of WPC:PUL led to more desirable physical and mechanical properties; in other words, lower rates of thickness, moisture content, water solubility and water vapour permeability, and higher elongations were achieved. Application of BW (especially in higher contents) could successfully improve colour indices, diminish water solubility (nearly 12%) and water vapour permeability (approximately 3×10(-11)gm(-1)s(-1)Pa(-1)), and increase tensile strength (by about 7MPa) of WPC-PUL blend films. Our edible films enjoyed great whiteness and ignorable yellowness indices, making it a suitable alternative for application in food products. Overall, WPC70-PUL30 containing 30% BW resulted in the best performance of physical and mechanical aspects as an optimum film.

Optimization of physical and mechanical properties for chitosan-nanocellulose biocomposites.

Chitosan (CHT) is a biodegradable compound and has excellent performance in forming films; on the other hand, nanocellulose (NCL) crystals have low densities and are less expensive than other nanofillers. A novel and simple method was applied to develop CHT-NCL nanocomposite (NCP) from CHT powder of high molecular weight and NCL particles having two dimensions in nanoscale; a rotor stator and an ultrasound device were used to separate different nanolayers from each other and facilitate their dispersion into polymer matrix. The optimized NCP indicated superior mechanical properties compared with some synthetic films; approximate values of 47% elongation-at-break, 245MPa tensile strength and 4430MPa Young's modulus were achieved. Water vapour permeability (WVP) value of the NCP was at optimal level of 0.23×10(-11) (g/msPa) which was much less than the most biofilms' WVP values. FESEM analyses revealed that high concentrations of CHT and NCL composed inter-connected structures justifying high elongation capability of CHT-NCL NCP.

Thermal and antimicrobial properties of chitosan-nanocellulose films for extending shelf life of ground meat.

Chitosan-nanocellulose biocomposites were prepared from chitosan having molecular weight of 600-800 kDa, nanocellulose with 20-50 nm diameters and various levels of 30, 60 and 90% (v/wCHT) for glycerol. Agitation and sonication were used to facilitate even dispersion of particles in the polymer matrix. The nanocomposites were examined by differential scanning calorimetry, X-ray diffraction and agar disc diffusion tests; finally, the film was applied on the surface of ground meat to evaluate its performance in real terms. Chitosan-nanocellulose nanocomposites showed high Tg range of 115-124°C and were able to keep their solid state until the temperature (Tm) range of 97-99°C. XRD photographs revealed that nanocellulose peak completely disappeared after their addition to chitosan context. Agar disc diffusion method proved that the nancomposite had inhibitory effects against both gram-positive (S. aureus) and gram-negative (E. coli and S. enteritidis) bacteria through its contact area. Application of chitosan-nanocellulose nanocomposite on the ground meat decreased lactic acid bacteria population compared with nylon packaged samples up to 1.3 and 3.1 logarithmic cycles at 3 and 25°C after 6 days of storage, respectively.