Application of nano-encapsulated olive leaf extract in controlling the oxidative stability of soybean oil

The enhancement of pistachio green hull extract functionality via nanoliposomal formulation: studying in soybean oil

Phenolic compounds of pistachio green hull extract (PGHE) were incorporated into nanoliposomes (NLs). The NLs were prepared with different concentrations of phenolic compounds of PGHE (500, 750 and 1000 ppm) and particle size, polydispersity index (PDI), zeta potential and encapsulation efficiency (EE) were investigated. The antioxidant activity of free and incorporated phenolic compounds of PGHE were evaluated in soybean oil during 39 days of storage by measuring peroxide (PV), thiobarbituric acid (TBA) values and color. The total phenolic content and IC₅₀ (DPPH assay) of PGHE were 614.91 ± 0.45 mg gallic acid equivalent/g fresh weight of extract and 10 ± 0.05 μg/ml extract, respectively. The prepared NLs had 101.86-105.81 nm size and PDI = 0.202-0.235. The zeta potential value of NLs varied between -47.7 and -52.3 mV. The highest EE (32.47%) was observed for NLs containing 1000 ppm of phenolic compounds. The lowest PV and TBA values were related to free phenolic compounds at 500 mg/kg oil. In comparison with free phenolic compounds, loaded NLs had lower antioxidant activity, but encapsulation could improve the stability, gradual release and solubility of phenolic compounds in soybean oil. The color of NLs containing oil samples remained constant during the storage, but free phenolic compounds changed the oil`s color. All concentrations of free and incorporated phenolic compounds had also higher antioxidant activity than BHT. Finally, 500 ppm of phenolic compounds of PGHE in its incorporated forms could be recommended as a substitute for synthetic antioxidant in soybean oil.

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

BACKGROUND

Olive leaves (OL), available in huge amounts from pruning, are known to be a useful source of biologically active compounds. This study investigated the potential application of OL as a supplement to minced beef meat in order to develop a functional product. The effect of OL extract or powder (100 and 150 µg phenols g^-1 meat) on the quality and stability of raw and cooked meat during refrigerated storage was examined.

RESULTS

Microwave drying at 600 W gave OL with the highest antioxidant quality (evaluated by TEAC/[phenols] (mg mg^-1 ) and DPPH/[phenols] (mg mg^-1 )) compared with other methods. OL showed an ability to inhibit (P < 0.05) lipid oxidation (TBARS values (mg MDA kg^-1 ) were reduced by 25-65%) and myoglobin oxidation (metmyoglobin production was 43-65% in control samples and 14-35% in treated samples). OL also improved the technological quality of the meat, decreasing (P < 0.05) storage loss (%) and defrosting loss (%) without affecting cooking loss (%) and Napole yield (%). Sensory properties were not modified by the added ingredient at the tested levels (P < 0.05).

CONCLUSION

OL (extract or powder) may have applications in the development of functional meat products of good technological quality that remain stable during storage. © 2016 Society of Chemical Industry.

Antioxidant effect of leaf extracts from Cressa cretica against oxidation process in soybean oil

Phenolic compounds from Cressa cretica leaves were extracted using different solvents (water and ethanol 70%) during 3-24 h by immersion method and were determined according to the Folin-Ciocalteu method. The antioxidant activities of the extracts were investigated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, ferric reduction activity potential and total antioxidant capacity assays compared with synthetic antioxidant namely BHT. The results were shown that the most total phenol content was outcome of the ethanolic extract after 18 h (68.512 ± 0.36 mg gallic acid/g dry extract) extraction. The results of different assays for determination of antioxidant potential of the extracts as well as their EC50 values were indicated antioxidant activities in order: BHT>ethanolic extract>aqueous extract. Also, the antioxidant activities were enhanced with increasing of the extracts and BHT concentrations. The results of Peroxide value (PV) and Thiobarbituric acid (TBA) tests were revealed that the ethanolic extract with various concentrations (200-1000 ppm) were suppressed the oxidation of soybean oil. The highest oxidation inhibitor was belonged to 1000 ppm concentration of the ethanolic extract so that can be good alternative for BHT.

Nanotechnology Approaches for Increasing Nutrient Bioavailability

Health-promoting ingredients such as phenolic compounds, vitamins, and minerals are being increasingly introduced into foods and beverages to produce "functional foods" specifically designed to improve human health, well-being, and performance. However, it is often challenging to incorporate these nutraceuticals into foods because they have poor solubility characteristics, impart undesirable flavor profiles, are chemically unstable, or have low bioavailability. This problem can often be overcome by encapsulating the bioactive components in nanoparticle-based delivery systems. The bioavailability of encapsulated bioactive agents often increases when the size of the particles containing them decreases, due to their faster digestion, ability to penetrate the mucus layer, or direct uptake by cells. Nanoparticles can be formulated to survive passage through specific regions of the gastrointestinal tract and then release their payload at a specified point, thus maximizing their potential health benefits. Nutraceutical-loaded nanoparticles can be fabricated through lipid formulations, natural nanocarriers, specialized equipment, biopolymer nanoparticles, and miscellaneous techniques. Classification into these five groups is based on the main mechanism or ingredient used to fabricate the nanoparticles. This chapter focuses on the utilization of food-grade nanoparticles for improving the performance of nutraceuticals in functional foods and beverages.

Preparation of a multiple emulsion based on pectin-whey protein complex for encapsulation of saffron extract nanodroplets

The present study illustrates a simple and practical way to produce an adequate delivery system of bioactive compounds of saffron by protein-polysaccharide complex. Frist, crocin, safranal, and picrocrocin were loaded in nanodroplets (<100nm) by using water in oil (W/O) microemulsions contain 5, and 10% aqueous saffron extract as a dispersed phase. These microemulsions were then covered with whey protein concentrate (WPC)-maltodextrin or WPC-pectin-maltodextrin through water in oil in water (W/O/W) multiple emulsions. The stability and release of loaded crocin, safranal, and picrocrocin in multiple emulsions were investigated during 22days storage. The produced multiple emulsion by WPC-pectin-maltodextrin along with 5% inner aqueous phase showed a high stability and low release of encapsulated compounds over time. This emulsion also provided a high protection of crocin, safranal, and picrocrocin in the gastric condition.

Optimization of a green extraction method for the recovery of polyphenols from olive leaf using cyclodextrins and glycerin as co-solvents

Olive leaf, an agricultural by-product, was studied for the valorization of its biophenols using green extraction techniques; i.e. non-toxic and eco-friendly extraction solvents were used, involving water and glycerol. 2-hydroxypropyl-β-cyclodextrin (CD), was also employed as an enhancer of the extraction, since cyclodextrins (CD's) are known to improve the extractability of olive leaf polyphenols by forming water soluble inclusion complexes. The process was optimized by implementing a central composite (Box-Behnken) experimental design and response surface methodology, taking into consideration the following independent variables: glycerol concentration (C_gl), CD concentration (C_CD) and temperature (T). The evaluation of the extraction model was based on two responses: the total polyphenol yield (Y_TP) and the antiradical activity (A_AR). Optimum values for the extraction process were obtained at 60% (w/v) glycerol content, T = 60 °C and 7% (w/v) CD content. LC-MS analysis was also applied in order to characterize the polyphenolic composition of extracts containing cyclodextrins. The main polyphenols present were oleuropein and oleuropein derivatives. Olive leaf aqueous extracts containing glycerol and cyclodextrins may be used as raw materials/ingredients for several end-users in the food, cosmetic and pharmaceutical industries.

Optimization of folic acid nano-emulsification and encapsulation by maltodextrin-whey protein double emulsions

Due to susceptibility of folic acid like many other vitamins to environmental and processing conditions, it is necessary to protect it by highly efficient methods such as micro/nano-encapsulation. Our aim was to prepare and optimize real water in oil nano-emulsions containing folic acid by a low energy (spontaneous) emulsification technique so that the final product could be encapsulated within maltodextrin-whey protein double emulsions. A non ionic surfactant (Span 80) was used for making nano-emulsions at three dispersed phase/surfactant ratios of 0.2, 0.6, and 1.0. Folic acid content was 1.0, 2.0, and 3.0mg/mL of dispersed phase by a volume fraction of 5.0, 8.5, and 12%. The final optimum nano-emulsion formulation with 12% dispersed phase, a water to surfactant ratio of 0.9 and folic acid content of 3mg/mL in dispersed phase was encapsulated within maltodextrin-whey protein double emulsions. It was found that the emulsification time for preparing nano-emulsions was between 4 to 16 h based on formulation variables. Droplet size decreased at higher surfactant contents and final nano-emulsions had a droplet size<100 nm. Shear viscosity was higher for those formulations containing more surfactant. Our results revealed that spontaneous method could be used successfully for preparing stable W/O nano-emulsions containing folic acid.

Ivy leaves extract based – lipid nanocarriers and their bioefficacy on antioxidant and antitumor activities

Two issues were addressed in the paper: (1) the use of medicinal herbs as functional ingredients entrapped into lipid-based nanocarriers; (2) the efficacy of phytochemical-based nanocarriers with promising antioxidant and antitumor benefits.

Crocin loaded nano-emulsions: Factors affecting emulsion properties in spontaneous emulsification

Spontaneous emulsification may be used for encapsulating bioactive compounds in food and pharmaceutical industry. It has several advantages over high energy and other low energy methods including, protecting sensitive compounds against severe conditions of high energy method and its ability to minimize surfactant, removal of cosurfactant and thermal stability compared with other low energy methods. In this study, we examined possibility of encapsulating highly soluble crocin in W/O micro-emulsions using spontaneous method which further could be used for making double emulsions. Nonionic surfactants of Span 80 and polyglycerol polyricinoleate (PGPR) were used for making micro-emulsions that showed the high potential of PGPR for spontaneous method. Surfactant to water ratio (SWR%) was evaluated to find the highest amount of aqueous phase which can be dispersed in organic phase. Droplet size decreased by increasing SWR toward the SWR=100% which had the smallest droplet size and then increased at higher levels of surfactant. By increasing SWR, shear viscosity increased which showed the high effect of PGPR on rheological properties. This study shows in addition to W/O micro-emulsions, spontaneous method could be used for preparing stable O/W micro-emulsions.