In Vitro Digestibility, Biological Activity, and Physicochemical Characterization of Proteins Extracted from Conventionally and Organically Cultivated Hempseed (Cannabis sativa L.).

The proteins from two conventionally (CC1 and CC2) and one organically cultivated (OC) hempseed samples were extracted (by alkaline solubilization followed by isoelectric precipitation) and compared in terms of their physicochemical, digestibility and in vitro bioactivity properties. The OC hempseed had higher total protein and lower nonprotein nitrogen content. Protein extracts showed bimodal particle size distributions, with OC showing the smallest and CC1 the largest mean particle diameter (d(0.5)), i.e., 89.0 and 120.0 µm, respectively. Chromatographic analysis showed similar protein profiles for all three protein extracts. The protein extracts were subjected to in vitro simulated gastrointestinal digestion (SGID). Degree of hydrolysis (DH) measurement showed that the highest extent of digestion upon SGID was associated with CC1 (11.0 ± 1.5%), which also had the lowest in vitro antioxidant activity. Only the OC and OC digested samples had lipase inhibitory activity. The results indicate that the cultivation method impacted the composition, physicochemical, digestibility, and biofunctional properties of hempseed proteins.

Purification of an antiviral protein from the seeds of quinoa (Chenopodium quinoa Willd.) and characterization of its antiviral properties.

Plant viral pathogens cause damaging diseases in many agriculture systems, and emerging viral infections are a serious threat for providing adequate food to a continuously growing population. Recent studies of biogenic substances have provided new opportunities for producing novel antiviral agents. The present work has been conducted to evaluate the antiviral activity of quinoa (Chenopodium quinoa Willd.) seeds crude extract. The antiviral activity was retained in different buffer solutions of various pH ranges (5.2-8.5) and remained after the diafiltration process. The putative virus inhibitor was sensitive to treatment with sodium dodecyl sulfate and trichloroacetic acid. An antiviral protein with ~ 25 kDa molecular weight was isolated from the seed quinoa extract using ammonium sulfate precipitation, anion and cation exchange chromatography. The purified protein (Quinoin-I) significantly inhibited TMV on tobacco leaves with an IC50 value at a 6.81 µg/ml concentration. Enzyme activity assay revealed the RNase activity of Quinoin-I, and this feature was retained in the presence of ß-mercaptoethanol and ethylene diamine tetraacetic acid. This antiviral protein has been shown as a promising leading molecule for further development as a novel antiviral agent.

Extraction and Characterization of Protein Concentrates from Limpets (Patella vulgata) and Peptide Release Following Gastrointestinal Digestion.

This study investigated the characterization of proteins from the Irish limpet (Patella vulgata) and assessed the in vitro biological activities of hydrolysates obtained following gastrointestinal digestion (INFOGEST) of a limpet protein concentrate (LPC). The physicochemical properties and the digestibility of the LPC were investigated, along with the angiotensin-converting enzyme (ACE) inhibition and antioxidant activities of the LPC-digested samples. All the digested samples examined outperformed the LPC in terms of activity. Peptides were identified using LC-MS/MS after digestion. A total of 38 and 19 peptides were identified in LPC-G and LPC-GI, respectively, using a database search and a de novo approach. Most of the identified peptides had hydrophobic amino acids, which may contribute to their antioxidant and ACE inhibitory activities. The findings of this study showed that LPC has high nutritional quality with good digestibility and could serve as a potential source of antioxidative and ACE inhibitory peptides following gastrointestinal digestion.

Eco-friendly 'ochratoxin A' control in stored licorice roots - quality assurance perspective.

According to toxicity data, ochratoxin A (OTA) is the second most important mycotoxin and is produced by Aspergillus and Penicillium. As a natural antifungal agent, clove essential oil (CEO) is a substance generally recognised as safe (GRAS) and shows strong activity against fungal pathogens. Here, we aimed to investigate the control efficacy of CEO in nano-emulsions (CEN) against OTA production in licorice roots and rhizomes during storage. The experiments were performed under simulated conditions of all four seasons (i.e. Spring, Summer, Autumn and Winter). Relative humidity (RH) and temperature were simulated in desiccators along with various salt solutions in incubators. Fresh licorice roots were immersed in CEN at various concentrations (150, 300, 600, 1200 and 2400 µl/l). Before utilising the nano-emulsions, we measured their polydispersity index and mean droplet size by the dynamic light scattering (DLS) technique. Also, the chemical composition of the CEO was determined using GC and GC-MS analyses. Sampling was carried out to monitor OTA once every five days. The samples were dried immediately and analysed by high-performance liquid chromatography (HPLC). Results showed that various concentrations of CEN inhibited the growth of fungi and OTA production. The most effective CEN concentrations were 1200 and 2400 µl/l, which reduced OTA production to 19 and 20 ppb under Winter and Autumn conditions, respectively. These results suggest an effective eco-friendly method for the storage of licorice to reduce postharvest fungal decay.

Insolubility in milk protein concentrates: potential causes and strategies to minimize its occurrence.

Milk protein concentrates (MPCs), which are produced from skim milk following a series of manufacturing steps including pasteurization, membrane filtration, evaporation and spray drying, represent a relatively new category of dairy ingredients. MPC powders mainly comprise caseins and whey proteins in the same ratio of occurrence as in milk. While bovine MPCs have applications as an ingredient in several protein enriched food products, technofunctional concerns, e.g., reduced solubility and emulsification properties, especially after long-term storage, limit their widespread and consistent utilization in many food products. Changes in the surface and internal structure of MPC powder particles during manufacture and storage occur via casein-casein and casein-whey protein interactions and also via the formation of casein crosslinks in the presence of calcium ions which are associated with diminishment of MPCs functional properties. The aggregation of micellar caseins as a result of these interactions has been considered as the main cause of insolubility in MPCs. In addition, the occurrence of lactose-protein interactions as a result of the promotion of the Maillard reaction mainly during storage of MPC may lead to greater insolubility. This review focuses on the solubility of MPC with an emphasis on understanding the factors involved in its insolubility along with approaches which may be employed to overcome MPC insolubility. Several strategies have been developed based on manipulation of the manufacturing process, along with composition, physical, chemical and enzymatic modifications to overcome MPC insolubility. Despite many advances, dairy ingredient manufacturers are still investigating technical solutions to resolve the insolubility issues associated with the large-scale manufacture of MPC.

Development of a natamycin-based non-migratory antimicrobial active packaging for extending shelf-life of yogurt drink (Doogh).

A natamycin-based non-migratory antimicrobial packaging for extending shelf-life of yogurt drink (Doogh) was developed. Firstly, the surface of low-density polyethylene film (LDPE) was modified with acrylic acid at different times of UV exposure (0-10 min) to produce carboxylic functional groups. Then, natamycin was applied to the UV-treated films to bind covalently with the pendent functional groups. The maximum grafting efficiency (81.96%) was obtained for the 6 min treated film. Moreover, surface properties of films were evaluated by Attenuated Total Reflectance/Fourier Transfer Infrared Spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Antifungal activity of different treatments of natamycin grafted film was evaluated against two common spoilage yeasts of Doogh including Rhodotorula mucilaginosa and Candida parapsilosis. Results showed that 6 min treated film provides maximum anti-yeast activity and can be applied to control fungal growth in Doogh. Natamycin-grafted film postponed the yeast spoilage in Doogh and prolonged its shelf-life to 23 days.

Electrospinning of glutelin-hordein incorporated with Oliveria decumbens essential oil: Characterization of nanofibers.

In this study, electrospinning of hordein and glutelin extracted from barley was carried out. Different ratios of the glutelin-hordein blends (25:75, 30:70, 35:65) were tested and the operation parameters including voltage, ejection flow rate and needle-to-collector distance were optimized. According to the scanning electron microscope images, the glutelin-hordein 25:75 blend generated at the voltage of 15 kV, the needle-to-collector distance of 150 mm and the ejection rate of 1 mL/h was selected for the fabrication of uniform nanofibers. The apparent viscosity at the ejection point was decreased with increasing the glutelin concentration from 25 to 35 %. Moreover, the Oliveria decumbens essential oil (ODEO) with different loading concentrations (2-4 % (v/v)) was incorporated into the protein blend. Fourier-transform infrared spectra demonstrated the occurrence of the interactions of proteins the ODEO. The encapsulation efficiency of ODEO in the nanofibers was 79.30 %. The presence of ODEO led to inhibition the growth of Staphylococcus aureus, Escherichia coli and Bacillus cereus in a synthetic medium. The optimal nanofibers showed high antioxidnat activity. The results herein showed the possibility of the production of electrospun nanofibers using barley proteins with promising (bio)functionalities for the active food packaging applications.

Investigation of the flowability, thermal stability and emulsification properties of two milk protein concentrates having different levels of native whey proteins.

Milk protein concentrate-85 (MPC85) is a dairy ingredient which has a diverse range of applications in food products. The technofunctional properties of two MPC85 samples having similar gross composition but different levels of native whey protein (WP), i.e., MPC85S1 and MPC85S2 with 16.6 and 6.0 g native WP/100 g protein, respectively, were compared. Rheometeric analysis showed that under an applied normal stress of 1.0-15.0 kPa, the compressibility, the air permeability and the cohesiveness of MPC85S2 was higher compared to MPC85S1. Differential scanning calorimetry showed that protein denaturation in MPC85S1 began at 63 °C while for MPC85S2 it began at 70 °C. The heat coagulation time (HCT at 140 °C) for 4.2% (w/v, on a protein basis) reconstituted MPC85S1 and MPC85S2 was 2.2 and 2.7 min, respectively. While a higher lightness for MPC85S1 was evidenced using colourimeter analysis, the colour stability on oven drying at 95 °C for MPC85S2 was higher than MPC85S1. The emulsion produced with MPC85S1 flocculated after 1 d and phase separation occurred after 14 d. In the case of MPC85S2, flocculation began after 4 d while phase separation was observed at 33 d. The viscosity of MPC85S2 (4.2% (w/v) protein) was higher than MPC85S1. This study showed differences between the flowability, viscosity, colour properties, thermal stability (in powder and in reconstituted format), emulsification and buffering capacity for MPC samples having two different levels of WP denaturation. The results demonstrated that the MPCs studied having two different levels of WP denaturation could be targeted for different functional applications. The minimal/maximum level of denaturation required to induce technofunctional property differences requires further study.

Semi-continuous production of xanthan in biofilm reactor using Xanthomonas campestris.

Semi-continuous production of xanthan gum using self-immobilized Xanthomonas campestris cells in biofilm reactors was studied. Fermentation was carried out using two different designs of biofilm reactor equipped with a) stainless-steel support (SSS) and b) polyethylene support (PES). Fermentation was performed in three cycles with refreshing the media at the beginning of each: cycle 1, 0-27 h; cycle 2, 27-54 h; and cycle 3, 54-78.5 h. Results showed that the glucose consumption and the pH reduction in the PES biofilm reactor was faster compared to the SSS biofilm reactor. Scanning electron microscopy showed that the SSS was capable to immobilize more cells during the growth of X. campestris. The maximum concentration of xanthan gum in the SSS biofilm reactor obtained after 27 h (3.47 ± 0.71 g/L), while the maximum concentration of xanthan in the PES biofilm reactor obtained after 78.5 h (3.21 ± 0.68 g/L). Thermal stability analysis of xanthan using differential scanning calorimetry showed the presence of two fractures attributed to dehydration and degradation of polymer. The thermogram represented both endothermal and exothermal behaviour of xanthan polymer. Furthermore, the functional groups and molecular structure of the xanthan produced in this study was evaluated using Fourier transform infrared spectrometry and also proton nuclear magnetic resonance. in addition, the surface tension of (0.2 %, w/v) xanthan gum solution was in a range of 52.16-56.5 mN/m. Rheological analysis of xanthan showed that the G' values were higher than the G″ in all frequencies demonstrating a relatively high elasticity of the produced xanthan gum.

Gum arabic improves the mechanical properties of wild almond protein film.

In this study, different films were manufactured using protein isolate extracted from wild almond (WAPI) in combination with different ratios of gum arabic (GA). Based on the mechanical properties of films including tensile strength (TS), elongation (E), and water vapor permeability (WVP), WAPI-GA with the ratio of 9:1 was selected. Accordingly, the mixture was incubated (T = 60 °C, RH = 79%) for 3, 6 and 9 days in order to conjugate WAPI with GA. Analysis of the films showed that after 6 day incubation, TS and E value were increased, while WVP was significantly reduced. Longer reaction presented adverse effects. SEM analysis of the films revealed the enhancement of compactness, and reducing of porosities after glycation. Differential scanning calorimetry showed that WAPI-GA incubated for 6 days have higher onset (Tonset) and endset (Tendpoint) temperatures than the control sample. The shifts in FTIR spectra after conjugation the confirmed occurrence of interaction between WAPIs and GA.

Antioxidant activity and ACE-inhibitory of Class II hydrophobin from wild strain Trichoderma reesei.

There are several possible uses of the Class II hydrophobin HFBII in clinical applications. To fully understand and exploit this potential however, the antioxidant activity and ACE-inhibitory potential of this protein need to be better understood and have not been previously reported. In this study, the Class II hydrophobin HFBII was produced by the cultivation of wild type Trichoderma reesei. The crude hydrophobin extract obtained from the fermentation process was purified using reversed-phase liquid chromatography and the identity of the purified HFBII verified by MALDI-TOF (molecular weight: 7.2kDa). Subsequently the antioxidant activities of different concentrations of HFBII (0.01-0.40mg/mL) were determined. The results show that for HFBII concentrations of 0.04mg/mL and upwards the protein significantly reduced the presence of ABTS(+) radicals in the medium, the IC50 value found to be 0.13mg/mL. Computational modeling highlighted the role of the amino acid residues located in the conserved and exposed hydrophobic patch on the surface of the HFBII molecule and the interactions with the aromatic rings of ABTS. The ACE-inhibitory effect of HFBII was found to occur from 0.5mg/mL and upwards, making the combination of HFBII with strong ACE-inhibitors attractive for use in the healthcare industry.

Ochratoxin A in liquorice products - a review.

Liquorice is a herbal medicine produced mainly in China and Iran. This plant is suspected to contain ochratoxin A (OTA), a secondary metabolite produced by fungi. Although liquorice is not included in the daily dietary of humans, the high levels of OTA reported in this product have concerned consumers. Registration of a standard method for measuring the amount of this mycotoxin in liquorice-derived products is an important challenge and requires the introduction of a reliable, simple, fast-performance and reproducible technique. This review examines studies carried out concerning the occurrence of OTA in liquorice products. Recent information regarding contaminated liquorice, the regulatory framework and methods to degrade OTA in liquorice are discussed.

Recent Advances in Fungal Hydrophobin Towards Using in Industry.

Fungal hydrophobin is a family of low molecular weight proteins consisting of four disulfide bridges and an extraordinary hydrophobic patch. The hydrophobic patch of hydrophobins and the molecules of gaseous CO2 may interact together and form the stable CO2-nanobubbles covered by an elastic membrane in carbonated beverages. The nanobubbles provide the required energy to provoke primary gushing. Due to the hydrophobicity of hydrophobin, this protein is used as a biosurfactant, foaming agent or encapsulating agent in food products and medicine formulations. Increasing demands for using of hydrophobins led to a challenge regarding production and purification of this product. However, the main issue to use hydrophobin in the industry is the regulatory affairs: yet there is no approved legislation for using hydrophobin in food and beverages. To comply with the legislation, establishing a consistent method for obtaining pure hydrophobins is necessary. Currently, few research teams in Europe are focusing on different aspects of hydrophobins. In this paper, an up-to-date collection of highlights from those special groups about the bio-chemical and physicochemical characteristics of hydrophobins have been studied. The recent advances of those groups concerning the production and purification, positive applications and negative function of hydrophobin are also summarised.

Conserved class of queen pheromones stops social insect workers from reproducing.

A major evolutionary transition to eusociality with reproductive division of labor between queens and workers has arisen independently at least 10 times in the ants, bees, and wasps. Pheromones produced by queens are thought to play a key role in regulating this complex social system, but their evolutionary history remains unknown. Here, we identify the first sterility-inducing queen pheromones in a wasp, bumblebee, and desert ant and synthesize existing data on compounds that characterize female fecundity in 64 species of social insects. Our results show that queen pheromones are strikingly conserved across at least three independent origins of eusociality, with wasps, ants, and some bees all appearing to use nonvolatile, saturated hydrocarbons to advertise fecundity and/or suppress worker reproduction. These results suggest that queen pheromones evolved from conserved signals of solitary ancestors.

The effects of temperature and relative humidity on ochratoxin A formation in fresh liquorice root.

In this study, the effects of temperature and relative humidity (RH) on ochratoxin A (OTA) formation during liquorice root storage were investigated. For this purpose, a real storage procedure in which fresh root was dried in the open air was simulated. Four RH-temperature combinations corresponding to average climate conditions (RH-temperature) of each season in an important liquorice growing and processing region were simulated as follows: A, autumn (T = 15°C, RH = 49%); B, winter (T = 9°C, RH = 51%); C, spring (T = 22°C, RH = 35%); and D, summer (T = 29°C, RH = 27%). The crushed fresh roots were incubated for 60 days, and the OTA content of the roots was determined at 20-day intervals by using inverse ion mobility spectrometry. The results showed that the maximum levels of OTA occurred after 40 days and were 4.3 ± 1.1, 0.9 ± 0.2, 7.3 ± 0.0 and 24.2 ± 2.5 ngg(-1) in roots stored under simulated conditions A, B, C and D, respectively. After 40 days, the amount of OTA started to decline in all samples but at different rates. The results seem to indicate that temperature plays a more significant role than RH in producing OTA by moulds in liquorice root. It appears that 22°C could be considered as the critical temperature for OTA formation in liquorice root stored under experimental conditions. It could be concluded that liquorice-processing plants should obtain, dry and store fresh moist root when the temperature is below the critical point. Moreover, the roots stored in the open shade condition should not be covered by plastic films even when it is raining as this increases the root temperature.

The effects of different ecophysiological factors on ochratoxin A production.

Mycotoxin biosynthesis is affected by peculiar agro-ecosystem dependent conditions. Accordingly, the correlation between mycotoxin contamination and environmental condition change scenarios should be carefully considered. This is because fungal colonization and mycotoxin contamination could critically impair the availability of food products, especially in poor countries. At any time, the agricultural products might become susceptible to fungal contamination and mycotoxin production in uncontrolled storage. From 2000 to 2010, many studies were carried out in the case of the effects of different parameters on ochratoxin A (OTA) production by fungi in order to avoid providing the appropriate conditions for producing OTA. Water activity (a(w)), temperature, type of species and the substrates were introduced as the most important in these articles. This paper reviews the major published articles regarding the different ecophysiological factors influencing on OTA production.

Determination of ochratoxin A in licorice root using inverse ion mobility spectrometry.

Despite the recent, successful efforts to detect mycotoxins, new methods are still required to achieve higher sensitivity, more simplicity, higher speed, and higher accuracy at lower costs. This paper describes the determination of ochratoxin A (OTA) using corona discharge ion mobility spectrometry (IMS) in the licorice root. A quick screening and measuring method is proposed to be employed after cleaning up the extracted OTA by immunoaffinity columns. The ion mobility spectrometer is used in the inverse mode to better differentiate the OTA peak from the neighboring ones. After optimization of the experimental conditions such as corona voltage, injection port temperature, and IMS cell temperature, a limit of detection (LOD) of 0.010 ng is obtained. Furthermore, the calibration curve is found to be in the range of 0.01-1 ng with a correlation coefficient (R(2)) of 0.988. Licorice roots were analyzed for their OTA content to demonstrate the capability of the proposed method in the quantitative detection of OTA in real samples.