Grapefruit Seed Extract and Lemon Essential Oil as Active Agents in Corn Starch–Chitosan Blend Films

The effect of lemon essential oil (LEO) and grapefruit seed extract (GSE) addition to starch–chitosan blend films on their functional properties and the associated structural changes were studied. Likewise, the films’ antioxidant properties and antimicrobial activity against some molds and Gram (+) and Gram (?) bacteria was evaluated. Composite active films exhibited a yellowish color, especially in the case of LEO addition. Film microstructure was analyzed by SEM evidencing a good incorporation of GSE to film matrix, while LEO droplets were dispersed in the polymer blend. Oxygen and water vapor barrier properties were not notably modified by the presence of active agents. FTIR analyses revealed that hydrogen bonding occurs in the blend films as the main interaction mechanism between components. Films containing LEO or GSE were less stiff and resistant but more stretchable than the control ones, being this effect concentration dependent. No notable antimicrobial action was observed in the films, which suggest that the required final concentration of active compounds must be fitted considering the minimum inhibitory concentration (MIC) values for a specific microorganism and its release kinetics to the food matrix.     

Improvement of solubility and Emulsifying Properties of Soy Protein Isolates by Glucose Conjugotion

Soy Protein Isolate(SPI)was modified with glucose(G-) through the amino-carbonyl reaction (Maillard Reaction).Solubility and emulsifying properties of the modified proteins were investigated.G-SPI conjugate was highly soluble at wide pH while untreated SPI was hardly soluble especially at pH4-PH6.Solubility of modified SPI showed the resistance to heat treatment and high ionic concentration.Emulsifying activity and emulsion stability of G-SPI conjugate was much higher than those of native SPI were.Comparing with some commercial emulsifiers,the G-SPI conjugate showed as good or better emulsifying properties in high salt concentration and in neutral pH.SDS-PAGE was also used to confirm the formation of G-SPI conjugate.     

Physicochemical Characterization of Lemongrass Essential Oil–Alginate Nanoemulsions: Effect of Ultrasound Processing Parameters

The formation of lemongrass oil (1 %?v/v) nanoemulsions in aqueous sodium alginate solution (1 %?w/v) containing Tween 80 (1 %?v/v) as nonionic surfactant was studied in terms of droplet size, electrical charge, viscosity, and whiteness index considering different ultrasonication times (0, 30, 60, 120, and 180 s) and amplitudes (30, 60, and 100 μm). The droplet size and size distribution of the emulsions decreased at increasing treatment time and amplitude. The minimum average droplet size observed in nanoemulsions was 4.31?±?0.18 nm with a narrow size distribution. The interface electrical charge of the coarse emulsion was ?18.0?±?2.9 mV, whereas in ultrasonicated nanoemulsions, it diminished up to ?55.8?±?6.4 mV when the sonication time was extended for 180 s. The viscosity of nanoemulsions also decreased at increasing treatment time and amplitude. Moreover, nanoemulsions became translucent after sonicating for 180 s at 30, 60, or 100 μm with whiteness indices of 28.61?±?0.17, 27.93?±?0.21, and 27.86?±?0.33, respectively. Therefore, it can be stated that ultrasound processing might be a feasible technology to produce highly translucent lemongrass oil–alginate nanoemulsions, with extremely small droplet sizes and high stability to be used as delivery systems of essential oils in food products. However, it is necessary to investigate the effect of ultrasound processing parameters on the antimicrobial potential of essential oils incorporated to nanoemulsions.     

Influence of Homogenization Conditions on Physical Properties and Antioxidant Activity of Fully Biodegradable Pea Protein–Alpha-Tocopherol Films

In this study, antioxidant biodegradable films based on pea protein and alpha-tocopherol were successfully developed by solution casting. The effect of both the homogenization conditions (rotor–stator and microfluidizer) and the relative humidity (RH) on the microstructure and physical properties (transparency, tensile, oxygen and water vapour barrier properties) of pea protein/alpha-tocopherol-based films was evaluated. The addition of alpha-tocopherol produced minimal changes in the films’ transparency, while providing them with antioxidant properties and improved water vapour and oxygen barrier properties (up to 30 % in both water vapour and oxygen permeability) when films were at low and intermediate RH. The addition of alpha-tocopherol in microfluidized films gave rise to an increase in their resistance to break and extensibility (up to 27 % in E values) at intermediate and high RH. These results add a new insight into the potential of employing pea protein and alpha-tocopherol in the development of fully biodegradable antioxidant films which are of interest in food packaging.     

Effect of Spray Nozzle Design on Fish Oil–Whey Protein Microcapsule Properties

Abstract: Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.     

Constituents,Oxidant-Antioxidant Profile,and Antimicrobial Capacity of the Essential Oil Obtained from Ferulago Sandrasica Peşmen and Quézel

Chemical constituents, total phenolic content, total oxidant status, total antioxidant status, lipid hydroperoxides, total free –SH levels, and antimicrobial activity of essential oil obtained from the Ferulago sandrasica (Umbelliferae) were investigated. The essential oil was obtained by hydrodistillation using a Clevenger-type apparatus. The chemical constituents were analyzed by gas chromatography‐mass spectrometry. The main components of the essential oil were ocimene (30.5%), carene-δ-3 (27.4%), and α-pinene (17.8). The antimicrobial activity was tested by a disc diffusion method against E. coli MC 400, E. coli ATCC 25922, E. coli 0157 H7, E. colaecea ATCC 23355, E. feacalis ATCC 19433, P. aeruginosa NRRL B-2679, S. aureus ATCC 25923, B. nischenoformis NRRL B-1001, S. aureus ATCC 33862, B. cereus NRRL B-3711, B. subtilis NRRL B-209, M. luteus NRRL B-1013, L. monocytogenes ATCC 7644, B. subtulis ATCC 6633.     

Effect of Packaging and Basil Essential Oil on the Quality Characteristics of Whey Cheese “Anthotyros”

In this study, we compared the effect of basil essential oil (EO) and various packaging conditions on “Anthotyros,” a Greek whey cheese. This cheese was stored at 4 °C under aerobic (A), vacuum (V), and modified atmosphere (M, 40%/60%; CO₂/N₂,) conditions, without or with (AB, VB, and VM) basil EO added to the cheese samples to a final concentration of 0.4% (v/w). The quality characteristics and the shelf life of both untreated and basil EO-treated cheese were assessed using microbiological, physicochemical, and sensory parameters. Microbiological results revealed that either modified atmosphere/vacuum packaging (MAP/VP) singly or in combination with basil EO delayed microbial growth as compared to the control (A) samples. The sensory and microbiological data showed that the combined use of MAP and VP with added basil EO extended the shelf life of fresh Anthotyros (4 °C) by approximately 10–12 days (treatment MB) and 6 days (treatment VB) as compared to aerobic packaging (A). Under these treatments, whey cheese samples maintained good sensory characteristics. This study has shown that the combined use of either VP or MAP, and basil EO, can extend the shelf life of whey cheese and maintain the freshness and the sensorial characteristics of the product.     

Essential oil composition,phenolic compound,and antioxidant potential of Inulaviscosa as affected by extraction process

The purpose of this study was to compare the essential oil composition of Inula viscosa leaves by hydrodistillation (HDE), ultrasonic (UDE) and solvent (SE) extractions followed by hydrodistillation. The total polyphenol and flavonoid contents and their antioxidant effects were studied by different solvent of extraction: ethanol (ET), ethyl acetate (EA), methanol (ME) and aqueous (AE). The principal compounds for HDE were: 2-hexenal (3.70%), caryophyllene oxide (3.11%), γ-selinene (3.09%), 3-hexen-1-ol (2.00%), eugenol (1.70%) and trans-caryophyllene (1.34%), while for UDE were: γ-selinene (5.68%), caryophyllene oxide (4.87%), trans-caryophyllene (1.99%) and nerolidol (1.74%). The oil obtained by SE was shown to contain tridecane (3.89%), dodecane (3.08%), trans-caryophyllene (2.94%), caryophyllene oxide (2.56%) and nerolidol (2.53%). Significant changes on phenolic contents were found between the different solvent of extraction. ME and AE extracts led to the highest total polyphenol (PHL) and flavonoid (FL) amounts. The anti-radical activity and reducing power were maximal in AE and ME extract. HPLC examination established that the ferulic acid as major phenolic acid in ME and AE fractions, whereas luteolin was the main compound of EA and ET fractions.     

Determination of Total Phenolic Content in Olive Oil Samples by UV–visible Spectrometry and Multivariate Calibration

The viability of determining the total phenolic content in olive oil samples by chemometric analysis of UV?Cvis spectral data was studied. As a result, a novel spectrophotometric method that does not require prior analyte separation is proposed. The method uses partial least squares (PLS) regression modeling in conjunction with UV?Cvis absorption spectral data obtained on oil samples dissolved in hexane. The resulting PLS model was developed by correlating the total phenolic content determined by Folin?CCiocalteu assay with the spectral data of oil solution between 210 and 340?nm. The predictive ability of the model was good as indicated by the root mean square error of prediction (RMSEP) and relative error (6.7?mg?kg^?1 and 6.1%, respectively) obtained for analysis of the validation set of samples. The principal figures of merit, namely limit of detection (7.3?mg?kg^?1), analytical sensitivity (1.0?mg?kg^?1) and precision (<10% RSD) were considered adequate for routine analysis. The proposed method was applied in the determination of total phenolic content in Chilean extra virgin olive oil (VOO) samples from the 2009 and 2010 harvest period. The results were compared to those determined with liquid chromatography.     

Physicochemical,Antioxidant, In Vitro Release,and Heat Sealing Properties of Fish Gelatin Films Incorporated with β-Cyclodextrin/Curcumin Complexes for Apple Juice Preservation

The antioxidant activity of gelatin film is poor. Curcumin is a natural antioxidant, but its main disadvantage is low aqueous solubility. In this study, curcumin was encapsulated by β-cyclodextrin to prepare βCD/CUR complex. Gelatin films incorporated with βCD/CUR complexes (GL-βCD-CUR films) were fabricated. The effects of curcumin content on their properties were investigated. Results showed that the water solubility of curcumin was improved in βCD/CUR complex. The βCD/CUR complex containing 2.5 mg curcumin had smaller size and more homogeneous distribution. The thicknesses of all films were about 87 μm and there were no significant differences (p > 0.05). The optimal tensile strength (TS) and elongation at break (EAB) of GL-βCD-CUR films were observed at the curcumin content of 2.5 mg. With the increase of curcumin concentration, water vapor permeability (WVP) of gelatin-based films decreased from 2.88 to 2.38 × 10^?10 g m^?1 Pa^?1 s^?1 and water content (WC) decreased from 34.64 to 24.72%, but water solubility (WS) increased from 21.22 to 59.75%. GL-βCD-CUR films exhibited lower light transmission in UV light compared with GL-βCD film. SEM provided that there was a good compatibility between gelatin molecules and βCD/CUR complexes. FTIR proved that no functional groups appeared or disappeared. A significant increase in antioxidant activity and the stability of this activity along with a lower release rate of curcumin in food simulant were observed in gelatin films incorporated with βCD/CUR complexes. The heat sealing property of GL-βCD-CUR films containing 1 or 2.5 mg curcumin was better than that of film containing 5 mg curcumin. The L values of red Fuji (Malus pumila mill) apple juice packed by GL-βCD-CUR films reduced slowly. The slowest decline in total polyphenol content was found in GL-βCD-2.5CUR group. Our results indicated that the incorporation of βCD/CUR complex significantly enhanced the antioxidant activity of gelatin film, and the GL-βCD-CUR film can be used in apple juice preservation.     

Analysis of α-Cryptoxanthin, β-Cryptoxanthin, α -Carotene,and β-Carotene of Pandanus Conoideus Oil by High-performance Liquid Chromatography (HPLC)

Pandanus conoideus is an endemic plant of Papua, Indonesia, reported to be very rich in carotenoids. The purpose of this study was to develop method for the determination of carotenoids (α-cryptoxanthin, β-cryptoxanthin, α-carotene and β-carotene) in P. conoideus oil (PO) by high-performance liquid chromatography (HPLC). sing the proposed method in this research, carotenoids content of nine clones of PO were analyzed which ranged from 5.4-138.5 ng/mg for α-cryptoxanthin, 3.9-29.4 ng/mg for β-cryptoxanthin, 3.5-80.0 ng/mg for α-carotene, and 10.8-118.0 ng/mg for β-carotene. Our results showed that four carotenoids content was very small as compared to total carotenoids content (3027-19959 ng/mg). This suggests that those four carotenoids were not a major component of the PO carotenoids. Using the principal component analysis, nine clones of P. conoideus can be grouped based on the proximity of its carotenoid content into group A (Monsor, Mbarugum, Himbiak, Monsrus and Memeri), group B (Menjib Rumbai), and group C (Edewewits, Hibcau and Hityom).     

Structure–mechanism relationship of antioxidant and ACE I inhibitory peptides from wheat gluten hydrolysate fractionated by pH

The aims of this study were to assess bioactive properties (ACE inhibition and antioxidant capacity) from wheat gluten hydrolysate peptides fractionated by pH (4.0, 6.0 and 9.0), to determine peptide action mechanism, and to relate it to the secondary structure and functional groups of peptides. Gluten hydrolysate extracts (GHE) were enriched in peptides with medium hydrophobicity and molecular weight (≈ 60% MH and 5.5 kDa, respectively). Gluten peptides inhibited ACE I by uncompetitive mechanism and a direct relationship between α-helix structure and IC50% value was obtained (r = 0.9127). TEAC and cooper chelating activity from GHE 6.5 were the highest and directly correlated with MH peptides. GHE 9.0 had high carotene bleaching inhibition (47.5 ± 0.3%) and reducing power activity (163.1 ± 2.9 mg S₂O₃^2 − equivalent g^− 1 protein), which were directly related to disulfide bonds content of peptides (r = 0.9982 and 0.9216, respectively). pH was a good alternative to select bioactive peptides from wheat gluten hydrolysate.     

Antioxidant power,bacteriostatic activity,and characterization of white grape pomace extracts by HPLC–ESI–MS

Polyphenolic fractions obtained from white grape pomace by aqueous extraction were analyzed to determine their antioxidant power (DPPH and TBARS methods), bacteriostatic activity, the effect of particle size on total extractable polyphenols (expressed as gallic acid equivalents (GAE)), and to characterize by HPLC–ESI–MS. The extraction of polyphenols from Albariño variety grape pomace was performed both on lab-scale and on pilot-plant scale using particles sizes of <1 mm, 3–5 mm and entire particle. Lab-scale assays showed that the lower the particle size the higher the raw extract (RE) percentage (%w/w), which values were 21.3 ± 0.37% (SD), 12.6 ± 0.38%, and 6.6 ± 0.44%, respectively. Several fractions were obtained from RE, either as result of applying liquid–liquid partition or gel permeation chromatography. The antiradical activities of the fractions were lower than that of gallic acid (17.8 ± 0.1 mg GAE/mol DPPH) but similar to that of catechin or procyanidin B₂ (46.0 ± 2.3 mg GAE/mol DPPH and 52.3 ± 6.3 mg GAE/mol DPPH). Several fractions showed bacteriostatic activity both at 50 and at 100 mg/L. Total aerobic bacterial enumeration (TABE, log UFC/cm²) of treated samples revealed a significant lower TABE than that for control. HPLC–ESI–MS studies demonstrated that fractions V and VI included monomers, dimers, and trimers of procyanidins, few of them galloylated. Fraction VII contained several oligomers and galloylated procyanidins.     

Effect of HPMC–Anthocyanin Packaging Color and Oxygen Permeability on Salmon Oil Preservation

Antioxidant food packaging films were successfully developed by incorporation of anthocyanin compound (liquid extract from natural sources) into hydroxypropyl methylcellulose matrix. Film color and oxygen barrier properties were measured. Red color of films containing anthocyanin compound (AC) showed good control of light transmission in comparison with control (transparent) films. Barrier properties of these films showed that addition of AC decreased oxygen permeability, possibly due to hydrogen bonding between polymer OH groups and those of anthocyanin compound. The effectiveness of bioactive films was investigated by packaging salmon oil. Changes in oil color, headspace oxygen consumption, conjugated dienes, polyene index, and C–H stretching vibration of cis-double bond (=CH) showed that, in general, AC films improved salmon oil stability. Films with 2, 3, and 4 % (v/v) AC offered the best protection against lipid oxidation due to improved barrier properties against light and oxygen.     

Dielectric Properties of Sweet Potato Purees at 915 MHz as Affected by Temperature and Chemical Composition∗

A process for rapid sterilization and aseptic packaging of sweet potato puree using a continuous flow microwave system operating at 915 MHz has been successfully developed. In microwave processing, dielectric properties have a major role in determining the interaction between purees and the electromagnetic energy. The objective of this research was to determine how dielectric properties are affected by temperature and chemical composition of purees derived from thirteen sweet potato cultivars with varying flesh colors. Results indicated that temperature, moisture, sugar and starch content had a pronounced effect (p < 0.001) on dielectric properties measured from 15°C to 145°C at 915 MHz. Dielectric constant decreased with increasing temperature, while dielectric loss factor increased quadratically. Power penetration depth of all cultivars decreased with increasing temperature. Predictive equations were developed for dielectric constant (R²?=?0.82) and dielectric loss factor (R²?=?0.90) as a function of temperature, moisture, sugar, and starch. The predictive equations would be useful in determining the dielectric properties of sweet potato purees for the microwave processing technology.