Insect‐Resistant Food Packaging Film Development Using Cinnamon Oil and Microencapsulation Technologies

Insect‐resistant films containing a microencapsulated insect‐repelling agent were developed to protect food products from the Indian meal moth (Plodia interpunctella). Cinnamon oil (CO), an insect repelling agent, was encapsulated with gum arabic, whey protein isolate (WPI)/maltodextrin (MD), or poly(vinyl alcohol) (PVA). A low‐density polyethylene (LDPE) film was coated with an ink or a polypropylene (PP) solution that incorporated the microcapsules. The encapsulation efficiency values obtained with gum arabic, WPI/MD, and PVA were 90.4%, 94.6%, and 80.7%, respectively. The films containing a microcapsule emulsion of PVA and CO or incorporating a microcapsule powder of WPI/MD and CO were the most effective (P < 0.05) at repelling moth larvae. The release rate of cinnamaldehyde, an active repellent of cinnamaldehyde, in the PP was 23 times lower when cinnamaldehyde was microencapsulated. Coating with the microcapsules did not alter the tensile properties of the films. The invasion of larvae into cookies was prevented by the insect‐repellent films, demonstrating potential for the films in insect‐resistant packaging for food products. Practical Application : The insect‐repelling effect of cinnamon oil incorporated into LDPE films was more effective with microencapsulation. The system developed in this research with LDPE film may also be extended to other food‐packaging films where the same coating platform can be used. This platform is interchangeable and easy to use for the delivery of insect‐repelling agents. The films can protect a wide variety of food products from invasion by the Indian meal moth.     

Development of Natural Insect‐Repellent Loaded Halloysite Nanotubes and their Application to Food Packaging to Prevent Plodia interpunctella Infestation

The aims of this study were to develop insect‐proof halloysite nanotubes (HNTs) and apply the HNTs to a low‐density polyethylene (LDPE) film that will prevent Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), commonly known as Indian mealmoth, from infesting the food. Clove bud oil (CO), an insect repellent, was encapsulated into HNTs with polyethylenimine (PEI) to bring about controlled release of CO. Chemical composition and insecticidal effect of CO were examined. The Fourier transform infrared ( FTIR) spectrum of encapsulated CO was confirmed. The surface charges of uncoated HNTs (HNTs/CO) and coated HNTs with PEI by the layer‐by‐layer (LBL) method (HNTs/CO/LBL) were determined to be –37.23 and 36.33 mV, respectively. HNTs/CO/LBL showed slow, controlled release of CO compared to HNTs/CO. After 30 d, the residual amounts of CO in HNTs/CO and HNTs/CO/LBL were estimated to be 13.43 and 28.66 mg/g, respectively. HNTs/CO/LBL showed the most sustainable repellent effect. HNTs applied to gravure printing ink solution did not affect mechanical, optical, or thermal properties of the developed film. Gravure‐printed LDPE film containing HNTs/CO/LBL displayed the greatest preventive effect on insect penetration, indicating its potential for use as insect‐resistant food packaging materials.     

Development of anti-insect food packaging film containing a polyvinyl alcohol and cinnamon oil emulsion at a pilot plant scale

Anti-insect packaging films containing cinnamon oil (CO) encapsulated by polyvinyl alcohol (PVA) for repelling Plodia interpunctella (Hübner) larvae were manufactured using pilot plant scale instruments. The microcapsule emulsion of CO and PVA was printed onto polypropylene (PP) film as an ink mixture using the gravure printing method. The printed PP film was then laminated with a low-density polyethylene (LDPE) film to protect the printed side. Four types of multilayer films were produced: control film, 2% CO film, encapsulated 1% CO film, and encapsulated 2% CO film. When mechanical properties were assessed, tensile strength and elongation-at-break were not significantly different among films, whereas the Young's modulus values were different between the control film and the three types of CO-containing films. In a repellent test, 2% CO film repelled P. interpunctella larvae most effectively. For sensory evaluation, which was performed using milk chocolate, caramel soft candy, and cookies packaged with the produced films, the produced films did not affect the sensory characteristics. Therefore, the films printed with emulsions of CO and PVA could be applied in the food industry to help protect foods from infestation by P. interpunctella.     

Repellency and attractancy of plant extracts against Plodia interpunctella and Sitophilus zeamais

Plodia interpunctella and Sitophilus zeamais are among the most destructive insect pests of stored processed food products. The use of natural materials rather than conventional pesticides to control these pests is a promising alternative to conventional neurotoxic insecticides. In this study, we tested organic extracts from 13 species of plants; most showed different effects on S. zeamais and P. interpunctella. Eleven of the extracts had repellent effects on S. zeamais but either an attractant effect or no effect on P. interpunctella. These results suggested that different species of insects have different reactions to plant extracts, and such extracts may have applications as storage products to prevent infestation by both P. interpunctella and S. zeamais.     

Efficacy of essential oils of Lippia alba (Mill.) N.E. Brown and Callistemon lanceolatus (Sm.) Sweet and their major constituents on mortality, oviposition and feeding behaviour of pulse beetle, Callosobruchus chinensis L

BACKGROUND: Pulse beetle, Callosobruchus chinensis L., is the most destructive insect pest of pulses under storage in Asia and Africa. Keeping in view the negative impacts of synthetic insecticides and the demands of botanical pesticides, the present investigation explores the repellents, antifeedants, ovicidal, larvicidal and pupaecidal activity of two plant essential oils (EOs) and their major components, geranial and 1,8‐cineole, when applied as fumigants for the management of the pulse beetle. RESULTS: EO of Callistemon lanceolatus (Sm.) Sweet caused 100% repellency of pulse beetle in a Y‐shaped olfactometer at a dose of 150 µL, while Lippia alba (Mill.) N.E. Brown EO and 1,8‐cineole showed 76 and 74.7% repellency at the same dose. At 0.1 µL mL^?1, both the oils and 1,8‐cineole provided 100% insect mortality. The EO of C. lanceolatus was recorded as the most effective fumigant, showing 96.03% oviposition deterrency and 100% antifeedant activity at 0.1 µL mL^?1. The LD₅₀ of L. alba (11049.2 µL kg^?1) and C. lanceolatus (14 626.3 µL kg^?1) exhibited their favourable safety profiles when recorded on mice. CONCLUSION: EOs of L. alba and C. lanceolatus exhibited significant biological activity on the mortality and reproductive behaviour of pulse beetle. Based on their high LD₅₀ values, the oils could be safely recommended as non‐mammalian toxic fumigants in management strategies for pulse beetle. Copyright © 2011 Society of Chemical Industry     

Color stability of frozen whole tilapia exposed to pre‐mortem treatment with carbon monoxide

BACKGROUND: Color of muscle foods plays a major role in consumer perception of meat quality. Carbon monoxide (CO) has been successfully used for improving color of packaged meat and fish products. In this study, we wanted to investigate pre‐mortem treatment of live tilapia using 100% CO for its ability to improve the color of frozen whole tilapia. We compared untreated and CO‐treated whole, gutted tilapia, frozen for 2 and 4 months at ? 20 °C. Frozen tilapia samples were thawed overnight at 4 °C, filleted and analyzed for their color, heme peak wavelength and CO concentration. RESULTS: Euthanasia using CO significantly increased redness (a* value) and lightness (L* value) of tilapia white and red muscle. Frozen storage significantly (P < 0.05) decreased redness of both CO‐treated and untreated tilapia. However, even after 4 months of frozen storage, a*‐value of CO‐treated tilapia was similar to fresh untreated tilapia fillets. Heme peak wavelengths of CO‐euthanized tilapia were higher than in untreated tilapia and there was no significant (P > 0.05) decrease in heme peak wavelengths of CO‐treated tilapia white and red muscle during frozen storage. The CO content of frozen euthanized tilapia fillets was significantly (P > 0.05) higher than in untreated fillets. In general, red muscle tissue of euthanized tilapia had a higher concentration of CO than white muscle. CONCLUSION: Color stability of tilapia fillets was significantly improved by pre‐mortem CO treatment. The color of CO‐treated fillets was retained during frozen storage compared to untreated fillets. Hence, pre‐mortem CO treatment could be used as a new method for improving color of tilapia. Copyright © 2008 Society of Chemical Industry     

Essential oil yield and composition of Pistacia vera ‘Kerman’ fruits,peduncles and leaves grown in California

BACKGROUND: Pistacia vera ‘Kerman’ is the predominant pistachio nut cultivar in the United States (California), the world's second largest producer. Despite several reports on the essential oil (EO) content in the genus Pistacia, data on ‘Kerman’ are limited. The EO content and volatile organic compound (VOC) emissions of tree nut orchards are of current interest to researchers investigating insect pests and the potential role of EO and VOCs as semiochemicals. To establish a basis for the VOC output of pistachios, the EO content of fruits, peduncles, and leaves was analyzed. RESULTS: Evaluated plant parts contained limonene as the primary EO component, followed by α‐terpinolene. Peduncles were unique in containing relatively high levels of α‐thujene. The results were reproducible between two different geographical locations. In situ solid phase microextraction (SPME) studies demonstrated the volatile emission was representative of the EO composition. CONCLUSION: This is the first report detailing the content and distribution of EO and the unique limonene‐dominant profile for this Pistacia vera cultivar which may influence pistachio insect pest semiochemical research. Copyright © 2010 Society of Chemical Industry     

Antibacterial activity of Thymus capitatus and Thymus algeriensis essential oils against four food‐borne pathogens inoculated in minced beef meat

The antibacterial activity of the essential oils extracted from Thymus capitatus and Thymus algeriensis was studied against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Pseudomonas aeruginosa. In this study, the disk method showed that T. capitatus EO has a strong antibacterial effect, whereas T. algeriensis EO showed a moderate activity. In addition, the inhibitory effect of both EOs was evaluated against four pathogenic strains inoculated experimentally (10⁸ CFU/g) in the minced beef meat, mixed with different concentrations of EOs, and stored for 15 days. Both EOs at low concentrations (0.01 and 0.05% [vol/wt]) exerted a bacteriostatic effect (p < .001), only against E. coli and S. typhimurium. However, at higher concentrations (1 and 3% [vol/wt]), the bactericidal activity was pronounced (p < .0001), in particular in the case of T. capitatus EO against all strains, except P. aeruginosa. The latter was still present after 15 days of storage, which explains its resistance.

Practical applications

Results from this study were confirmed that both thyme EOs could be considered as a very promising natural preservatives for foods from microbial spoilage in the food industries, also they can serve to inhibit or prevent the growth of food‐borne pathogens.     

Use of Electrolyzed Oxidizing Water for Quality Improvement of Frozen Shrimp

The bactericidal effect of electrolyzed oxidizing (EO) water was evaluated on Escherichia coli O157:H7‐inoculated and Salmonella‐inoculated shrimp. The shrimp were inoculated on day 0 and stored frozen at ‐20°C. Bacterial enumeration was done on days 0, 24, 49, and 119 of frozen storage. Acidic EO water at 40 ppm free available chlorine was as effective as aqueous chlorine of the same concentration and was significantly more effective (P < 0.05) than tap water in reducing pathogen load on the inoculated shrimp. Further reduction of pathogen numbers was observed after each frozen storage period. Prewashing with alkaline EO water did not enhance the bactericidal activity of the acidic EO water on the shrimp. The washed acidic EO water of the inoculated shrimp had a nondetectable bacterial population compared with treated aqueous chlorine, alkaline EO water, and tap water. Non‐inoculated shrimp subjected to similar treatments were served cooked or uncooked to a minimum of 10 experienced panelists for sensory evaluation on days 0, 24, 49, and 119 of frozen storage. The cooked shrimp were evaluated for the presence of off‐odor, juiciness, tenderness, shrimpy flavor, aftertaste, and overall acceptability; whereas the raw shrimp were evaluated for color, firmness, presence of off‐odors, melanosis, and overall acceptability. Raw shrimp thawed from each frozen storage period were stored at refrigeration temperature (4 °C) for 3 d to observe for melanosis. No difference of sensory attributes was detected among the various treatment groups. Therefore, acidic EO water can be used as an effective disinfectant to replace aqueous chlorine for thawing shrimp blocks.     

Antimicrobial Effects of Nisin,Essential Oil,and γ‐Irradiation Treatments against High Load of Salmonella typhimurium on Mini‐carrots

This study aimed at using essential oil (EO) alone or combined EO with nisin and γ‐irradiation to control Salmonella Typhimurium during the refrigerated storage of mini‐carrots. Peeled mini‐carrots were inoculated with S. Typhimurium at a final concentration of approximately 7 log CFU/g. Inoculated samples were coated by 5 different coating solutions: (i) nisin solution at final concentration of 10³ IU/mL; (ii) mountain savory EO solution at 0.35%; (iii) carvacrol solution at 0.35%; (iv) mountain savory EO at 0.35% plus nisin solution of 10³ IU/mL; or (v) carvacrol at 0.35% plus nisin solution of 10³ IU/mL. Coated mini‐carrots were then irradiated at 0.5 or 1.0 kGy and compared to an unirradiated control sample. Samples were kept at 4 °C and microbial analyses were conducted at days 1, 3, 6, and 9. The results showed that mini‐carrots coated by carvacrol plus nisin solution or mountain savory EO plus nisin solution in combination with irradiation at 1.0 kGy completely eliminated S. Typhimurium to under the detection limit during the storage. Thus, the combined treatments using carvacrol plus nisin or mountain savory EO plus nisin coating solution and irradiation at 1.0 kGy could be used as an effective method for controlling S. Typhimurium in mini‐carrots.     

Cumulative oxygen consumption during development of two postharvest insect pests: Callosobruchus maculatus Fabricius and Plodia interpunctella Hübner

Insect pests such as Callosobruchus maculatus Fabricius and Plodia interpunctella Hübner cause substantial losses to grain during postharvest storage. In the last few years, hermetic storage technologies have been successfully used by smallholder farmers in Africa and Asia to protect their harvested grain against insect pests. Hermetic technologies owe much of their effectiveness to restricting oxygen availability to insects confined in the containers. There is a need to better understand the biology of specific storage insect pests and their responses to hypoxia. We employed a novel and non-invasive analytical technology, the OxySense 5250i, to measure oxygen levels in closed containers, and evaluated its effectiveness in measuring the total oxygen consumption of two insect pests during their development: C. maculatus and P. interpunctella. The total amount of oxygen consumed by C. maculatus during its larval development period determined with the OxySense apparatus was not different from that previously recorded using another instrument, the Mocon Pac Check 325 gas analyzer. Using the OxySense 5250i, we found that P. interpunctella consumes nearly three times as much oxygen per insect over its larval-to-adult developmental period compared to C. maculatus. Information on the lifetime oxygen consumption of insects provides relevant information to the effectiveness and ability of hermetic technologies to protect stored products against insect pests.     

Characterization of cosmetic cream with Mesembryanthemum crystallinum plant extract: influence of formulation composition on physical stability and anti‐oxidant activity

Cosmetic or pharmaceutical composition containing superoxide dismutase (SOD) was usually used in topical administration, particularly, in fighting against skin ageing and in the protection of the skin against radiation exposure. Mesembryanthemum crystallinum is a halophyte plant widely used in the traditional medicine, characterized by the presence of anti‐oxidants enzymes in responses to abiotic stresses. In the present study, we prepared a formulation with M. crystallinum extract characterized by naturally occurring SOD and catalase in association with other anti‐oxidants molecules. The SOD activity was measured by 3‐(4,5‐dimethyldiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide/riboflavin method, catalase by colorimetric method and the total anti‐radical activity was measured by 1,1‐diphenyl‐2‐picrylhydrazyl radical (DPPH) method. Formulations contain a significant SOD activity (8.33 U mg^?1), a catalase activity (0.5 × 10⁷ UC) and an anti‐radical activity (30% of DPPH inhibition). The formulation storage (15 days at 4°C) showed a marked loss of total anti‐oxidant capacity. The addition of the M. crystallinum extract induced also a reduction in formulation viscosity and pH.     

Efficacy of Acorus calamus L. essential oil as a safe plant‐based antioxidant,Aflatoxin B1 suppressor and broad spectrum antimicrobial against food‐infesting fungi

The study explores the efficacy of Acorus calamus L. essential oil (EO) as a safe plant‐based broad spectrum antifungal, antiaflatoxin, antioxidant food additive. The oil completely inhibited the growth and toxin production of the toxigenic strain of Aspergillus flavus at 0.4 and 0.25 μL mL^?1, respectively. EO exhibited pronounced antifungal activity against sixteen food‐infesting fungal species at 0.5 μL mL^?1. The EO showed strong antioxidant efficacy (IC₅₀ 1.06 μL mL^?1) and nonphytotoxic nature on germination of chickpea seeds. The EO was found nonmammalian toxic showing high LD₅₀ (4877.4 μL kg^?1) for mice (oral, acute). The chemical profile of EO was determined through GC and GC–MS analysis. The findings strengthen the possibility of A. calamus EO as a plant‐based food additive in view of its favourable safety profile, antioxidant and antiaflatoxigenic efficacy and broad spectrum antimicrobial activity against food‐infesting fungi.     

Effects of Mentha longifolia L. essential oil and Lactobacillus casei on the organoleptic properties and on the growth of Staphylococcus aureus and Listeria monocytogenes during manufacturing,ripening and storage of Iranian white‐brined cheese

This research evaluated the effects of Mentha longifolia L. essential oil (EO) in concentrations 0, 50, 150 and 300 ppm and Lactobacillus casei (10⁸–10⁹ CFU/mL) on the growth of Staphylococcus aureus and Listeria monocytogenes during the manufacturing, ripening and storage of Iranian white‐brined cheese. The growth of the two pathogens was significantly reduced (P < 0.01) by both EO concentrations ≥50 ppm and probiotic and their combination in the standard manufacturing and storage process conditions of the cheese. Furthermore, the treatment containing 150 ppm of this EO combined with probiotic had a favourable inhibitory effect on the growth of two pathogenic micro‐organisms and also was the most appropriate treatment in sensory assessment. The synergistic effects of the above‐mentioned concentration level between the essential oil and probiotic were significant compared to other treatments, including essential oil and probiotic only. Thus, a lower concentration of this EO can be used when it is combined with this probiotic.     

Methoprene and synergized pyrethrins as aerosol treatments to control Plodia interpunctella (Hübner), the Indian meal moth (Lepidoptera: Pyralidae)

Aerosol insecticides (also known as ULV or fogging treatments) delivered through an ultra-low-volume application system, are available commercially to control insect pests such as Plodia interpunctella Hübner, the Indian meal moth. However, little is known about the susceptibility of eggs of P. interpunctella to aerosol insecticides applied in active field sites. We conducted several trials by exposing eggs of P. interpunctella to synergized pyrethrins, alone and in combination with the insect growth regulator methoprene. Eggs in diets and packaging materials containing the food products were directly exposed to the aerosols. There was significant variation among the food products, as assessed by adult emergence from exposed eggs, but in general there was no difference in adult emergence from eggs exposed to a 1% versus a 3% pyrethrin formulation when methoprene was included. There was no difference in efficacy between diets and diet packages placed in open areas versus areas that were in some way obstructed to the aerosol. Adult emergence was generally reduced in the treatment combinations compared to untreated controls. A partial budget analysis indicated that the combination treatment of 1% pyrethrins + methoprene represented the lowest risk, lowest cost, and would seem to be the optimum combination. Results show that field applications of aerosols could be used to control P. interpunctella in storage facilities.     

The preservation of the quality of the muscle in frozen Australian red claw crayfish (Cherax quadricarinatus) by pre‐storage anti‐oxidant dipping treatments†

Australian red claw crayfish tails were dipped in either 0.06% (w/w) anti‐oxidant solutions (tocopherols, propyl gallate, or rosemary extract) or in water and subsequently stored in a ?20 °C freezer. At the end of 0, 1, 3, and 6 months of storage, the raw muscle samples were analysed for lipid oxidation, the thermal stability of proteins, cooking yield and shear force. Red claw treated with anti‐oxidants showed a lower (P < 0.05) thiobarbituric acid‐reactive substances (TBARS) production than the non‐anti‐oxidant control (dipped in water). Enthalpy of denaturation (ΔH) for the myosin head and shear values for the tails decreased (P < 0.05) in all samples after 6 months of storage, while cooking yield was unaffected by storage. Overall, red claw muscle was quite stable and the oxidation, measured as TBARS values, was small (<0.3 mg kg^?1) but could be further stabilized by anti‐oxidant dipping treatments. However the anti‐oxidant dipping did not prevent texture softening in red claw muscle during frozen storage.     

Development of a 1-Methylcyclopropene (1-MCP) Sachet Release System

ABSTRACT The partitioning of 1‐methylcyclopropene (1‐MCP) between the gas/polymer matrix was determined for 2 adsorbing agents and 4 sachet materials to estimate the adsorption potential of 1‐MCP at 23°C. The release study was performed using a closed system under 2 different environmental conditions, dry air (0% RH) and 90% RH. Sachets made from Tyvek®, paper, low‐density polyethylene (LDPE), and polyvinyl acetate (PVA) materials were fabricated to contain silica gel and activated carbon. Activated carbon sachets did not release 1‐MCP at either testing condition. Activated carbon had a very strong affinity for 1‐MCP. The permeability coefficients of 1‐MCP and water in polyethylene and polyvinyl acetate films were determined using a quasi‐isostatic method. LDPE sachets containing silica gel had similar 1‐MCP release rates at both 0% and 90% RH. PVA sachets containing silica gel had slow release of 1‐MCP. The amount of 1‐MCP released from PVA sachets containing silica gel at 90% RH was larger than the amount of 1‐MCP released at 0% RH. Release of 1‐MCP from paper and Tyvek sachets was largely dependent on the sorbate‐absorbing ability of the adsorbing agents.     

Development of moisture‐absorbing and antioxidant active packaging film based on poly(vinyl alcohol) incorporated with green tea extract and its effect on the quality of dried eel

Active packaging film with functions of moisture‐absorbing and antioxidant activity was developed based on poly(vinyl alcohol) (PVA) incorporated with green tea extract (GTE). The effects of GTE concentrations of 0, 0.5, 1, 1.5, and 2% on the physical, structural, and antioxidant properties of PVA films were investigated. The PVA film containing 2% GTE had lower moisture absorbing efficiency relatively and better antioxidant activity through DPPH radical‐scavenging ability experiment. A packaging system of GTE‐incorporated PVA films was applied to package dried eel and quality of dried eel was evaluated during storage. The result showed that dried eel packed with GTE‐incorporated PVA films showed lower weight change, peroxide value and TBARS value during storage than that packed without PVA films or with PVA films but no GTE. The PVA film containing 2% GTE showed the best quality protective effectiveness to prevent the dried eel from absorbing moisture and oxidizing of lipid.

Practical applications

Poly(vinyl alcohol) (PVA) is a synthetic polymer that is widely used in packaging applications because of its excellent film forming, biodegradability, good mechanical, and gas barrier properties. The present study evidenced that the PVA films incorporated with GTE showed good quality protective effectiveness to prevent the dried eel packed with these films from absorbing moisture and oxidizing of lipid. This active packaging film could be used as inner layer or intermediate layer in the composite packaging film system to improve the storage quality of moisture‐sensitive and high‐fat food. Based on this concept, the moisture‐absorbing agents and antioxidant can be incorporated into the packaging structures to develop an active multifunctional food packaging material potentially to remove or reduce moisture inside the food packaging system instead of desiccants and preservative added in the food.