A similar experiment was performed with THC,this time only evaluating the FBBB stability at refrigerated temperatures.The characteristic red color indicative of the presence of THC did form; however,like the hemp,the color was duller than when performing the usual procedure.Finally,FBBB was preloaded onto PSPME substrates and left in refrigerated temperatures for a week and were then used to evaluate 1000 ppm THC and 1000 ppm CBD solutions.Red and orange colors did form,respectively,but they were duller like all the other chromophores formed using FBBB as a preloaded salt.There is a growing interest in natural bioactive compounds both by producers and consumers in the food and pharmaceutical industries.Particularly,consumers are looking for foods without artificial and harmful preservatives that can promote their health.Essential oils as natural food preservatives are,generally,extracted from medicinal plants and herbs for their noticeable biological activities.EOs are complex combination of secondary metabolites,including terpenoid hydrocarbons,phenol derivatives and oxygenated terpenoids ; however,due to having volatile components,their usage is limited; the volatile compounds can be degraded easily by adverse external conditions such as light,oxygen,temperature,pressure,and pH.In addition,controlled release of EOs is needed when used for specific purposes like food additives.In recent years,the isolation and utilization of EOs from agroindustrial wastes and by-products have gained much research interest.Industrial hemp’s inflorescences are usually discharged during the conventional hemp processing,resulting in an underused biomass for future uses.They are a rich source of EOs and contain mainly monoterpenes and sesquiterpene hydrocarbons like -caryophyllene,α-pinene,myrcene and α-humulene,which exhibit important biological activities.Valorization of hemp by-products is a matter of interest for producers,allowing them to increase the market value of hemp cultivation.Some studies have recently been carried out on the functional and pharmacological applications/properties of industrial hemp essential oil due to their antioxidant,trimming trays for weed antimicrobial,and anti-inflammatory activities.
There is much interest in developing biodegradable nanoparticles as an effective delivery system for delivering lipophilic food bioactives.Proteins are attractive options for designing polymeric NPs as suitable wall materials thanks to their amphiphilic nature compatible with many active substances,as well as excellent functional properties.Whey protein,as a typical cheese processing by-product,is commonly used to foods due to its great nutritional value and techno-functional properties such as gelling,foaming and emulsifying.Protein fibrillation is used nowadays for fabrication of protein fibrils having novel functionalities and improved structure stability.Heating the protein above 80 ◦C for 5–24 h at low ionic strength and acidic conditions can result in production of WPI fibrils ,which are more suitable as delivery carriers comparing to native proteins,due to having multiple functional groups,and thus,promoting different interactions with numerous and drugs and nutrients.Protein complexation has recently been proposed as a promising and efficient way for improving the bio-availability,chemical stability and dispersion of bio-active compounds in an aqueous environment.Mung bean protein is a significant plant protein that demonstrates high potential as sustainable protein source for its availability,nutritional value,hypoallergenic,and desirable foaming,emulsifying,gelling,and film-forming capabilities.The rainbow trout as an extremely perishable food belongs to the Salmonidae family.Recently,the demand for rainbow trout has increased remarkably,and this could be due to its desirable characteristics.Due to the demand for fresh refrigerated fish with extended shelf life,notable study has been directed toward prolonging the shelf life of this fish.Although,there are scarce studies on the characterization and fabrication of IHEO encapsulated in complexation of WP nanofibrils and MBP NPs.The present study is to manufacture and characterize WPNFMBP NPs as a novel wall material for loading IHEO.Furthermore,application of IHEO-reinforced WPNF-MBP NPs as a potential natural additive for increasing the shelf-life of Rainbow trout fillets during refrigerated storage is going to be evaluated.The chemical changes of Rainbow trout fillets were monitored through the measurement of TVB-N,TBA and PV values of the fish oil during storage.Hydroperoxides are the main products of lipid oxidation; thus,measurement of peroxide values is helpful for indicating oxidative rancidity.As depicted in Fig.3a,PV in the control samples increases from 1.33 to 8 meq O2/kg at day 10 and declines after this day,maybe due to the reaction of hydroperoxide with protein as well as the collapse of primary oxidation products into secondary oxidation products.PV level tends to increase toward the end of the storage period.
A similar pattern of hydroperoxide content has also been reported in Rainbow trout fillets during storage.The samples coated with WPNF-MBP and IHEO-reinforced WPNF-MBP NPs showed significantly lower PV levels than the control during the storage period.The literature considers a PV value of 20 meq O2/kg oil is as the maximum limit for fish.Our results indicated that the IHEO-reinforced WPNF-MBP NPs coating is significantly reduced the amount of primary lipid oxidation in fish during storage; this is in agreement with the results of other similar investigations.TBA index is a common indicator for evaluating the lipid oxidation level by measuring such oxidation products as aldehydes like malondialdehyde.The recommended perceivable level of TBA in food as objectionable odour is about 1–2 mg MDA/kg ; however,Raeisi et al.proposed the maximal acceptable level 5 mg MDA eq/kg in Rainbow trout with no negative effects on its safety and quality.As indicated in Fig.3b,the TBA level remained below the maximal acceptable level during the 14-day storage.However,in the uncoated samples,the TBA value was much higher than in the coated samples ; however,the initial value of TBA was in the range of 0.09–0.13 mg MDA/kg,consistent with reports of other researchers for fresh Rainbow trout.The slightly lower oxidation rate in the IHEO-reinforced WPNFMBP NPs coatings can be because of the oxygen barrier and antioxidant activity features of IHEO and WPNF.The antioxidant mechanism of IHEO can be due to its polyphenols,which show scavenging activity against free radicals through providing hydrogen atoms to free radicals,preventing radical chain initiation,and thus,preventing the formation of metal catalyzed free radicals.On the other hand,the WP coatings provided a great protection against oxidation.IHEO addition improved the WPNF-MBP NPs coatings’ antioxidant properties.WPs exhibit antioxidant activity through different ways: 1) formation of a coating,which is a good barrier for O2 permeability coated samples during storage,2) enjoying a free radical scavenging capacity by some amino acids and metal chelation by bovine serum albumin and lactoferrin,3) having sulfhydryl groups partially responsible for their antioxidant properties,and 4) containing β-lactoglobulins and α-lactalbumin with good antioxidant activity for having amino acid residues.Furthermore,particle size reduction of IHEO and WPNF-MBP coatings after nanoencapsulation can increase these ingredients’ specific surface; thereby achieving an efficient amount of free radical absorption would be achieved.
TVB-N is produced from degradation of proteins and non-protein nitrogenous compounds,mainly as a result of microbial and enzymatic activities,as an indicator of meat and fish spoilage.The TVB-N level in the control samples was initially 6.68 mg N/100 g,and there was no significant difference among the different samples at the first day of storage.By increasing the bacterial counts,the TVB-N value increased gradually in all groups; however,in the samples coated with WPNF-MBP and IHEO-reinforced WPNF-MBP NPs,the TVBN value was significantly lower than in the controls.Considering the maximal acceptable level of 25 mg N/100 g in fish flesh ,the TVB-N limit was achieved at day 8 of storage in the controls,while in the WPNF-MBP coated samples,this limit was reached by the 10th days,and in the IHEO-reinforced WPNF-MBP NPs coated samples,it was lower than this limit during the whole period of storage.At the last day of storage,the TVB-N value for the IHEO-reinforced WPNF-MBP NPs coated samples was 12.1 and 9 mg N/100 g lower than the control and WPNF-MBP coated samples,respectively.We previously mentioned that TVB-N is produced mainly because of the bacterial degradation of the nitrogenous compounds of proteins and non-protein products,its low value in the coated samples can be due to the microbial inhibitory effects of treatments that decrease the formation of TVB-N.Similarly,Shokri et al.found that coating of Rainbow trout fillets with chitosan-Ferulago angulate EO nano-emulsion retarded the increasing rate of TVB-N index during storage at 4 ◦C.Ozogul et al.found that nano-emulsions based on plant EOs significantly inhibited the TVBN formation in Rainbow trout fillets during ice storage.To the best of our knowledge,there are no studies on the effect of IHEO-reinforced WPNFMBP NPs coating on the formation of TVB-N in Rainbow trout fillets; however,trimming tray with screen the lower TVB-N in the samples coated with IHEO-reinforced WPNF-MBP NPs in the present work could result from the antibacterial efficiency of WPNF-MBP coating facilitated by nano-encapsulation of IHEO.Fig.4 illustrates the overall acceptable scores of the control and coated Rainbow trout fillets with WPNF-MBP and IHEO-reinforced WPNF-MBP NPs.In the present study,appearance,color,odor,and texture were taken into consideration in the overall acceptance scoring.The overall acceptance scores were in the range of 1–5.High preference levels represent high element scores.All samples exhibited high sensory and quality scores at the first day of analysis.An overall acceptance below 3 of fish is considered to be unacceptable for human consumption.The overall acceptance scores of the coated and control fish samples showed a decreasing trend up to the end of storage time.The samples coated with IHEO-reinforced WPNF-MBP NPs exhibited a higher score comparing to the other samples during the refrigerated storage.The control samples’ sensory properties were ‘unacceptable’ by the 10th day.Also,at the day 12,the samples coated with WPNF-MBP did not achieve acceptable scores due to their unpleasant appearance and sticky surface; however,the incorporation of IHEO reduced these defects.Hence,the samples coated with IHEO-reinforced WPNF-MBP NPs had better sensory scores than the others for control the lipid oxidation and bacterial population.
These results are consistent with the findings of O˘ guzhan Yıldız and Yangılar and Farsanipour et al.for Rainbow trout WP-based coated samples incorporated with EOs stored at refrigerator condition.Industrial hemp,Cannabis sativa L.is a multifaceted crop that is increasingly being considered by farmers looking to diversify and reduce their ecological footprint.Industrial hemp is grown for both fiber and food,and is also used in cosmetics and for medicinal and nutraceutical/ pharmaceutical purposes.A major factor contributing to the sustainability of hemp is that most parts of the plant can be used,and innovation is contributing to additional uses of hemp for biofuels,high-performance textiles and natural insecticides.Hemp has long been used as a food source and in traditional medicine ,and this has stimulated research into its use as a functional food.In addition to its healthy oil and protein profiles,several bioactive peptides have been found in hemp seed,as well as polyphenols and other effective antioxidants.Hemp seed should be relatively easy to get to food markets as seed processing can use existing production facilities with some adjustments.Hemp seed is actually an achene or nut,with a hard outer shell ,a papery testa,and an inner seed.Industrial hemp is classified as Cannabis plants with low levels of Δ9- tetrahydrocannabinol ,depending on the country and state.It was recently estimated that the global production of hemp will double in the four years from 2016 to 2020,and some states in Australia have already more than doubled their production.This resurgence of interest in hemp has led to an increasing number of states in the USA growing low THC hemp,and as of 2017 all states in Australia have legalized cultivation of industrial hemp for food and fiber applications.In comparison to other crops hemp has been described as sustainable because it is relatively resistant to biotic and abiotic stresses thereby reducing agronomic inputs.In temperate Australia industrial hemp is grown as a summer crop and requires supplemental irrigation.Hemp has a relatively high water requirement compared to dryland cereals,although much less than cotton.A major advantage of hemp from an agronomic point of view is the rapid growth of seedlings such that it effectively outcompetes weeds.This and the fact that it has relatively few pests and diseases makes hemp better suited for organic production than many other row crops.In Australia,some pests and diseases have been observed,but in most cases there has been no significant impact on productivity.Industrial hemp is suited to a wide variety of soil types as long as they are fertile with good drainage and water holding capacity.When C.sativa is grown for fiber,tall varieties are used because of their increased biomass.Shorter varieties are being bred with higher harvest index that are specifically targeted to food markets.Characterization of FINOLA seed showed that it contains approximately 30% oil and 25% protein.Analysis of lipids of FINOLA seed revealed that over 80% are polyunsaturated including two essential fatty acids,linoleic acid and α-linolenic acid.Hemp seed contains a ratio of omega-6 to omega-3 in a desirable range between 2:1 and 3:1.Current western diets are generally deficient in omega-3 fatty acids,with a high ratio of omega-6:omega-3,due to the increased intake of vegetable oils including sunflower and corn oils,which have ratios of >50:1 omega-6:omega-3.