Ham Cubes Research Articles

Efficacy of a carboxymethylcellulose (CMC)-based edible film with propylene glycol to control ham mite populations that infest dry cured ham

Dry-cured hams are susceptible to ham mite, Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae), infestations during the aging process. Methyl bromide (MB) fumigation has been used to control mites from infesting hams. However, MB is an ozone depleting substance that is both expensive and scarce, so alternative control methods must be discovered. The objective of this research was to determine the efficacy of using an edible film to control or reduce mite growth and reproduction on dry-cured hams. The edible films consist of water, 1% of carboxymethylcellulose (CMC), and propylene glycol (PG), which was included at five concentrations: 0%, 5%, 10%, 15%, and 20%. The resulting films’ ability to reduce mite infestation was tested against two control groups: exposed ham cubes (negative control) and ham cubes wrapped in polyester nets (positive control) containing 40% PG, 1% carrageenan, and 1% propylene glycol alginate. Two weeks after inoculation with 20 mites, all film treatments had fewer (P < 0.05) mites than the negative control (262-mites). Film treatments with 0% (24-mites), 5% (26-mites), and 10% PG (17 mites) were effective at slowing mite reproduction, but not to the extent of the positive control (0-mites), 15% (6-mites), and 20% (1-mite) PG films as evidenced by a linear decrease in mite counts (F1 = 19.22, P < 0.0001) as PG concentration increased. Water Vapor Transmission (WVT) and Oxygen Permeability (OP) results indicated that all films exhibited substantial breathability with values ranging from 805 g m−2 day−1 to 899 g m−2 day−1 for WVT and 355 cc m−2 day−1 to 3413 cc m−2 day−1 for OP. Sensory analysis results indicated that the film treatments did not alter the sensory properties of the treated hams when compared to the untreated control. Further studies will include application of films to whole hams during aging and improved manufacturing techniques for films.

Using liquid smoke to control infestations of the ham mite, Tyrophagus putrescentiae, on dry-cured hams during aging

Eight treatments of edible coatings and nets including liquid smoke (SP and 24P) and xanthan gum (XG) were used to evaluate their effectiveness at controlling mite growth on dry-cured hams. Mite growth was controlled (P < 0.05) in both coating and netting treatments of 1% SP + 1% XG. Increasing SP concentration from 1% to 2% in the SP only treatments without XG did not control mite growth (P > 0.05) in the coating but controlled mite growth (P < 0.05) when infused in the nets. Both coating and netting treatments with 2% 24P + 1% XG controlled mite growth (P < 0.05), and ham cubes with 1% and 2% 24P in infused nets had mite numbers of 4.6 and 9.4, respectively. SP did not impact the sensory attributes of the ham. Results indicate that liquid smoke can potentially be added in coatings or ham nets to control mites and used in an integrated pest management program for dry-cured hams.

Effectiveness of nets treated with food-grade coatings following various drying methods for controlling mite growth on dry-cured hams

Tyrophagus putrescentiae (Schrank), commonly referred to as the ham mite, may infest dry-cured pork during aging. Food-grade propylene glycol (PG) coated ham nets inhibit mite growth and reproduction, but there are application challenges, including shipping costs and handling. Therefore, the objective of this research aimed was to determine if the food-grade coating treated ham nets were still effective at controlling mite growth after drying. Using previously developed methods, polyester nets were coated with a food-grade solution of 40% PG, 1% propylene glycol alginate, and 1% carrageenan. Six treatments were evaluated: no net (NC), coated and wet net (WC), uncoated net (UC), oven-dried for 7 min at 93.3 °C (OD7m), oven-dried for 20 min at 93.3 °C (OD20m), and counter-dried at 22-23 °C for 24 h (CD24h). Ham cubes (2.5cm × 2.5cm × 2.5 cm) were wrapped in the nets (n = 5/trt) and inoculated with 20 adult mites. The cubes were stored in ventilated jars at 25 °C and 70% relative humidity for 14 d. Mites on each ham cube were counted after the 14 d incubation period. A randomized complete block design was used to determine if differences existed (P ≤ 0.05) among treatments. Duncan's multiple range test was used to separate treatment means when differences existed. The OD7m, CD24h, and WC treatments had fewer mites (P ≤ 0.05) than the OD20m and UC treatments; the C treatment had the greatest (P ≤ 0.05) mite count. The OD7m and CD24h treatments lost 37.3% and 36.5% of their starting weights, respectively, while OD20m lost 72.0%. The greater loss (P ≤ 0.05) for the OD20m treatment may have affected the treatment's efficacy. In addition, drying coated nets did not affect the mechanical quality of nets nor the sensory quality of hams when they were wrapped in dried coated nets.

The application of chitosan in food-grade coatings to control Tyrophagus putrescentiae on dry-cured hams and the effects on sensory properties

The objective of this research was to evaluate if chitosan-containing food-grade coatings can control Tyrophagus putrescentiae growth without affecting the sensory attributes of dry-cured hams. Food-grade coating treatments included (1) 0.3% chitosan (CH), (2) 0.6% CH, (3) 0.3% CH + 10% propylene glycol (PG), (4) 0.3% CH + 1% xanthan gum (XG), (5) 0.3% CH + 1% XG + 10% PG, (6) 0.3% CH + 1% carrageenan (CG) + 1% propylene glycol alginate (PGA), and (7) 0.3% CH + 1% CG + 1% PGA + 10% PG. Each coating solution was coated on ham cubes (2.54 × 2.54 × 2.54 cm3, n = 5/treatment) or infused in ham nets and dry-cured ham cubes were wrapped in the ham nets prior to inoculation with 20 adult mites. A randomized complete block design with three replications was utilized to evaluate the efficacy of treatments at controlling mite growth on dry-cured ham. When CH was mixed with XG (0.3% CH + 10% PG + 1% XG, and 0.3% CH + 1% XG) and infused into a net, fewer mites (15.7 and 21.0 mites) were on the ham cubes (P < 0.05) in comparison to the control (211.2 mites). Results indicate that CH has the efficacy to control mites since 1% XG alone did not control mite growth. Difference from control test results indicated that no sensory differences existed (NS) between CH-treated and control ham slices. The addition of chitosan coated nets helped control mite growth when used in conjunction with xanthan gum and propylene glycol and collectively may be useable as part of an integrated pest management plan for ham producers to control mites in their aging houses. Therefore, these coating solutions could be scaled up to evaluate their efficacy in ham aging houses.

Natural and Synthetic Repellents for Pest Management of the Storage Mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae).

Simple SummaryThe ham mite is the major pest of dry-cured hams, aged cheeses, and specialty pet foods that are high in fats and proteins. Ham mites are also known to cause allergies in some cases for humans. The toxic fumigant gas methyl bromide had been used for years to control this mite pest, but it is being phased out of use due to its impact on the protective ozone layer of the earth’s upper atmosphere. Ham producers now require alternatives to methyl bromide for controlling mites. We conducted laboratory experiments with food-safe synthetic and plant-derived chemical repellents to keep mites away from dry cured hams. Our results showed that several of these repellents could effectively prevent ham mites from contacting and staying on treated pieces of ham, and that they would readily go to untreated ham pieces when given a choice. Further experiments found that mites would not feed on nor produce offspring when held on ham pieces coated with oils from thyme, lemon grass, rose, or a mixture of naturally occurring fat molecules. Our experiments suggest that these food-safe repellents might protect dry-cured hams from mites during their time in aging rooms by application to racks on which hams are aged or to the nets and packaging in which hams are held.The fumigant pesticide methyl bromide (MB) was used for stored products, but it is now banned for most uses in many countries as an ozone-depleting substance. MB was the only pesticide used to manage the ham mite, Tyrophagus putrescentiae, which is the most significant pest of dry cured hams. Effective alternatives to MB are needed to develop integrated pest management (IPM) programs for this pest. This study evaluated plant essential oils and food-safe compounds as repellents to directly protect hams from infestation. Experiments to assess the repellency to orientation, oviposition, and population growth of mites on pieces of aged country hams were conducted. Test compounds at different concentrations were dissolved in respective solvents and compared to the solvent control. Results showed that C8910, a mixture of three short-chain fatty acids, and the sesquiterpene ketone nootkatone had repellency indices of (RI) of 85.6% and 82.3%, respectively, at a concentration of 0.1 mg/cm2, when applied to a Petri dish arena. DEET and icaridin were also tested but performed poorly with RIs below 70% even at 0.1 mg/cm2.The monoterpene alcohol geraniol had the highest RI of 96.3% at 0.04 mg/cm2. Ham pieces dipped in C8910 and nootkatone at 150 ppm each had RIs of 89.3% and 82.8%, respectively. In general, as the concentrations of test compounds increased, the numbers of eggs that were laid on these treated ham cubes decreased after the 48 h exposure time. Ham pieces dipped in different concentrations of test compounds and then inoculated with 20 adult mites showed a significant decrease in mite population growth compared to control pieces after 14 days. The results of these experiments suggest that some plant secondary metabolites and synthetic food-safe compounds could serve as potential alternatives for managing mites on hams.

The application of food grade short chain fatty acids to prevent infestation of Tyrophagus putrescentiae on dry cured ham and the effects on sensory properties

Tyrophagus putrescentiae (ham mite) is difficult for commercial dry cured ham producers to control. Methyl bromide is an effective fumigant but is now banned as an ozone depleting substance, meaning alternative methods to control mite infestation must be found. This research was conducted to test the efficacy of C8C9C10 fatty acids combined with and without food grade coatings to control mite infestations on dry cured hams. Ham cubes were coated directly or wrapped in nets saturated with C8C9C10 with combinations of either soybean oil, xanthan gum (XG) or carrageenan (CG) + propylene glycol alginate (PGA). Cubes were then inoculated with 20 large mixed sex ham mites and stored for 14 days at 22 ± 2 °C and 70 ± 5% relative humidity. The soybean oil alone or in combination with 10% C8C9C10 in direct coating, and 1% and 10% C8C9C10 in coated nets controlled mite population growth. In addition, the use of 10% C8C9C10 + XG and 10% C8C9C10 + CG + PGA in direct coatings or in saturated nets, and 1% C8C9C10 + XG in saturated nets also inhibited mite population growth. Unexpectedly, the soybean oil solvent by itself effectively controlled mite population growth as well. Sensory evaluation was performed using a difference from control test (n = 8) and indicated that only 10% C8C9C10 mixed with soybean oil and 100% soybean oil did not impart sensory differences to ham when used as a coating. However, for ham slices treated in saturated nets and gum with C8C9C10 mixtures in either coating or saturated nets did impart sensory differences. Results indicated that C8C9C10 and soybean oil could be used in coating formulations to control ham mites but long-term testing, sensory evaluation, and scaled up testing is needed prior to industrial implementation.

The effects of dry-cured ham initial water activity on Tyrophagus putrescentiae infestations

A 5 × 2 × 2 factorial arrangement within a completely randomized design was used to evaluate the effect of aw (0.65, 0.70, 0.75, 0.80, and 0.85), RH (65% and 75%) and temperature (24 °C and 28 °C) on Tyrophagus putrescentiae growth, on ham cubes in two separate experiments, one for treated nets (infused with propylene glycol (PG) + propylene glycol alginate (PGA) + carrageenan (CG) + water) and one for untreated control nets. For treated nets, water activity and temperature did not affect mite growth. When control nets were used, there was no difference due to aging temperature, but there were more mites (P < 0.05) at 65% RH than at 75% RH. In addition, ham cubes with 0.85 aw had more mites (P < 0.05) than at 0.70 and 0.65 aw, and ham cubes with 0.80 and 0.75 aw had more mites (P < 0.05) than at 0.65 aw. The only treatment combinations that controlled mites were the ham cubes with 0.65 aw that were stored at 75% RH at both temperatures, with average mite counts below the initial inoculum level of 20 mites. Overall, results indicated that the treated nets were effective at controlling ham mites, regardless of ham cube aw, storage temperature, and RH. However, if only untreated barrier nets were used, mites were only controlled when ham cubes had a aw of 0.65 or 0.70 and were stored at 75% RH. These conditions may not be practical since drying to 0.65 or 0.70 aw would result in more moisture loss, lower yields, and less product that could be sold.

Acaricidal effects of fresh garlic juice on adult ham mite, Tyrophagus putrescentiae (Schrank)

Ham mites, Tyrophagus putrescentiae (Schrank), are a common pest of dry cured meat products and cause devastating effects on product quality. Methyl bromide, a chemical fumigant used to control mite populations, is no longer be available due to regulatory action. Therefore, it is essential to identify potential alternatives. Garlic (Allium sativum) extracts or chemical components show toxicity to the northern fowl mite, mosquitoes, nematodes, and aphids. Thus, we explored the efficacy of garlic juice in controlling T. putrescentiae. Using a choice test experimental design, approximately 50% of inoculated mites colonized control ham cubes, while no mites remained on cubes dipped in fresh garlic juice. Garlic was ineffective when examined for volatile efficacy, but was toxic in direct contact assays, showing time- and concentration-dependent lethality. Fresh garlic juice at 50–100% strength showed ≥95% mortality in 24 h bioassays, well within the range for acceptable commercial efficacy. However, as fresh garlic juice aged up to 72 h, efficacy was significantly reduced, particularly when diluted with water. Thus, garlic juice acted as a short-term repellent and toxicant in contact models, but application is time sensitive. Nonetheless, it shows potential utility for control of the ham mite.

Effects of temperature, relative humidity, and protective netting on Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) infestation, fungal growth, and product quality of dry cured hams

Since methyl bromide is an ozone depleting substance, there is a need to find effective alternative methods to control mite infestations on dry cured hams. Therefore, the objective of this study was to determine the most effective relative humidity and/or temperature combination to minimize mite reproduction and mold growth on dry cured hams in untreated and food-grade ingredient infused nets. Food grade coating formulations of 1) xanthan gum and propylene glycol, and 2) carrageenan, propylene glycol alginate, and propylene glycol nets were infused into nets. Dry cured ham cubes and slices were wrapped with untreated and treated nets, inoculated with 20 large mixed-sex mites per cube or 50 large mixed-sex mites per slice, and then stored for 14 d at each temperature (24, 28, and 32 °C) and RH (55, 65, 75, and 85%) combination in an environmental chamber. Tyrophagus putrescentiae on ham slices in untreated nets were reduced from the initial inoculum level of 50 mites per ham slice when exposed to 85% r.h. at 24, 28, and 32 °C. Nets infused with xanthan gum and propylene glycol or carrageenan, propylene glycol alginate, and propylene glycol, completely inhibited mite reproduction at 85% r.h. In addition, the nets infused with carrageenan, propylene glycol alginate, and propylene glycol, controlled mite reproduction below the initial inoculum level on ham cubes and ham slices at all temperatures and relative humidities that were evaluated. Six to eight trained panelists rated the amount of mold on the ham slice surfaces on a 0–100% scale and both treated nets evaluated were effective at preventing mold growth on the ham slices.

Incorporating fermented by-products of Lactobacillus diolivorans in food grade coatings designed for inhibition of Tyrophagus putrescentiae on dry-cured hams

Distillate solutions that were derived from concentrated ferment of Lactobacillus diolivorans were incorporated into either a carrageenan (CG) and propylene glycol alginate (PGA) gum blend or into a CG, PGA, and xanthan gum (XG) blend. Fermented distillate was produced in a model system to mimic fermentation in food grade coatings to produce 1, 3 propanediol, acetic acid, and lactic acid. Distillate treatments were compared against a 10% propylene glycol treatment, a gum only control, and negative control on 2.5 × 2.5 × 2.5 cm cubes (n = 50) that were dipped into solutions prior to conducting mite bioassays. Coated and control ham cubes were inoculated with 20 adult T. putrescentiae (Schrank), and incubated for 2 and 3 weeks. The distilled treatments with CG + PGA + XG had a 20 fold or greater reduction (P < 0.05) in mite populations than all other treatments with the exception of the 10% PG coated treatments. In addition, there were no differences between treatments with respect to sensory texture, flavor, and moistness. This indicates that fermentation within food grade coatings could be evaluated on the surface of dry-cured ham to determine if the success in a model system could be reproduced in practice.

Use of Lard, Food Grade Propylene Glycol, and Polysaccharides in Infused Nets to Control Tyrophagus putrescentiae (Schrank; Sarcoptiformes: Acaridae) Infestation on Dry Cured Hams

Tyrophagus putrescentiae (Schrank) is controlled in the U.S. dry cured ham industry with methyl bromide (MB) fumigation. However, MB fumigation is being phased out of use since it is an ozone depleting substance. The objective of this research was to evaluate ham nets that were infused with lard, propylene glycol (PG) and polysaccharide coating for their efficacy at controlling mite infestations on dry cured ham cubes from hams that were aged for 4 to 6 mo. Results indicated that fewer T. putrescentiae (P &lt; 0.05) were on ham cubes with treated nets containing PG when compared to the number of mites on ham cubes with untreated nets over 10 wk of storage. Lard infused nets without PG did not decrease the mite population (P &gt; 0.05). The net without coating slowed the growth and reproduction of T. putrescentiae since net controls had fewer mites (P &lt; 0.05) than controls without nets. Fungi were not present on ham cubes that were treated with PG-containing nets over 10 wk of storage with a few exceptions. In conclusion, lard and xanthan gum, or carrageenan + propylene glycol alginate treated nets containing the medium concentration of PG effectively inhibited mite reproduction and fungal growth on dry cured ham and could potentially be used in an integrated pest management program to control mites on dry cured hams.

Use of nets treated with food-grade coatings on dry-cured ham to control Tyrophagus putrescentiae infestations without impacting sensory properties

Dry-cured hams may become infested with the ham mite Tyrophagus putrescentiae during aging. Food-grade coatings have been developed to control mite infestations as a potential alternative to replace methyl bromide, but dipping or spraying these coatings requires additional labor and processing steps. Nets composed of polyester, a polyester/cotton blend and cotton were infused with coatings that consisted of propylene glycol, and either propylene glycol alginate and carrageenan or xanthan gum. Results indicated that the polyester/cotton blend and cotton nets that contained propylene glycol were effective at controlling mite infestations in assays with ham cubes covered in nets. The polyester nets slowed mite growth but were not effective at controlling mite reproduction due to low absorbance of the coatings. Polyester/cotton blend nets treated with coatings on whole hams were not different from control hams with respect to flavor, texture and moistness. Mite infestation tests on whole hams indicated that coated nets with greater stitch densities were effective at controlling mite growth. Future research will include the optimization of coating formulations and scaled-up testing in dry-cured ham plants.

Impact of Relative Humidity and Net Treatments on Tyrophagus Putrescentiae (Schrank) Infestations and Mold Growth on Dry Cured Ham

ObjectivesDry cured hams are susceptible to mite infestations which are currently controlled in the U.S. dry cured ham industry via fumigation with methyl bromide. Since methyl bromide is an ozone depleting substance, food grade ingredient infused nets have been researched as an alternative to control mite infestations on dry cured hams. Mite infestations and mold growth vary on dry cured ham in untreated and treated nets due to environmental changes in relative humidity (RH) and temperature. Therefore, the objective of this research was to evaluate the effect of RH and infused nets on mite infestations and mold growth on dry cured hams.Materials and MethodsPatent pending food grade coating formulations consisting of 1) xanthan gum (XG) and propylene glycol (PG) and 2) carrageenan (CG), propylene glycol alginate (PGA), and PG were infused into ham nets. Dry cured ham cubes (2.5 cm3) and slices (2.5 cm × 9.0 cm × 15.5 cm) were wrapped with untreated (control) and 2 types of infused (treated) nets (XG + PG and CG + PGA + PG) and stored in ventilated glass jars. Three cubes and slices from each treatment were inoculated with 20 and 50 adult mites respectively, and stored in an environmental chamber for 14 d at 24°C and 65 ± 2, 75 ± 2, and 85 ± 2% RH. Mite infestation was determined by counting the mobile mites on ham cubes, slices, and nets using a microscope. Nine trained panelists rated the moldiness of ham slice surfaces on a 0 to 100% scale. A 3 × 3 factorial structure within a completely randomized design was used to determine the impact of RH and net treatment on mite infestations and mold growth. The least square means method was applied to separate treatment means.ResultsAt 65 and 75% RH, samples with treated nets had fewer (P < 0.05) mites than the control, but there were no differences (P > 0.05) between treated and control nets at 85% RH. On average, across net treatments, there were fewer mites (P < 0.05) at 75 and 85% RH in comparison to 65% RH. In addition, when averaged over RH, samples in XG and CG coated nets had fewer (P < 0.05) mites on ham slices compared to samples in untreated nets. Though there was no difference between XG and CG (P > 0.05) with respect to the number of mites on ham slices, the CG treatments were effective at controlling mites at all RHs. In contrast, the XG treatment did not control mites at 65% RH. There was a strong correlation (r = 0.98) between percentage of the ham slices covered with mold and number of mites present. Mold growth was greater (P < 0.05) at 65% RH in comparison to 75 and 85%, and XG and CG treatments had less mold growth than the control treatments, with the CG treatment completely inhibiting the presence of visual mold.ConclusionTreated nets inhibited mite infestations and mold growth on ham cubes at 65 and 75% RH and on ham slices at 65% RH. Results indicate that 75 and 85% RH would be more desirable in the ham industry if hams were aged at 24°C. Further testing will be performed to observe the impact of temperature on mite infestations and mold growth on ham cubes and slices at various RHs to optimize aging conditions that can used to help control mite infestations.

Application of Food-Grade Ingredients to Nets for Dry Cured Hams to Control Mite Infestations

Infestations of Tyrophagus putrescentiae (Schrank; Sarcoptiformes: Acaridae), known as the ham mite, may occur on dry cured hams during the aging process. The fumigant methyl bromide is currently used to control mite infestations, but it will eventually not be available for use since it contributes to the depletion of the ozone layer. The use of ham nets treated with xanthan gum, carrageenan, propylene glycol alginate, and propylene glycol food-grade ingredients on mite orientation to or oviposition on treated or untreated ham cubes, and mite reproduction and population growth over a 10-wk period was evaluated. Behavioral tests indicated that more than 95% of the mites oriented to the ham cubes that were wrapped in untreated nets when compared to treated nets and no eggs were laid on the latter. The reproduction assays demonstrated that there were fewer (P &lt; 0.05) T. putrescentiae produced over a 2-wk period on ham cubes covered with both gum and propylene glycol treated nets, when compared to the untreated or gum-only treated nets over the 10-wk storage period of the experiment. Medium and high concentrations of propylene glycol treatments showed the lowest reproductive rates of mites. No more than 4 mites could be found on each of these treatments in comparison to 200 to 300 mites that were recorded on the untreated hams. This study demonstrated efficacy of using the nets treated with food-grade ingredients during ham aging to control mite infestations on a laboratory scale. Further research will be conducted to determine the effectiveness of the same treated nets on whole hams in commercial aging rooms.

Application of Food Grade Coatings to Prevent Mite Infestion in Dry Cured Ham Processing Facilities

ObjectivesThe ham mite (Tyrophaus putrescentiae Schrank) is the predominant target pest for dry cured ham during aging. Methyl bromide is currently the only effective fumigant for controlling mite infestations in the dry-cured ham industry. However, methyl bromide is being phased out of all industries based on the Montreal Protocol. The objective of this research was to find viable, effective and economical alternatives for the dry cured ham processing facilities.Materials and MethodsFood grade coatings (patent pending) were made from combinations of 1) propylene glycol (PG), xanthan gum (XG), and water or 2) PG, propylene glycol alginates (PGA), carrageenan (CA) and water. Trials were conducted in the summers of 2014 and 2015 in 4 commercial processing facilities and a simulated aging house at Mississippi State University. Whole hams were dipped in coatings or applied to hams with a high pressure spray nozzle and aged for 5 to 8 mo. Difference from control sensory tests (6 to 10 trained panelists, 3 reps per plant) were conducted on ham slices that were removed from the treatment hams to determine the impact of the coatings on sensory quality.To make the coatings more applicable to the dry-cured ham industry, ham nets were infused with the coatings mentioned above and tested for their efficacy at controlling mite infestation. On the laboratory benchtop, 20 mites were inoculated onto single ham cubes (2.5cm × 2.5cm × 2.5cm) that were wrapped with ham nets that were treated with different coatings (n = 5/trt). Total numbers of mites were counted after 14 d of storage at 25°C and 70% relative humidity.Completely randomized design was utilized and Tukey’s test was used to separate the means for data analysis.ResultsControl and treated hams from the commercial trials in both years received sensory scores between 1.6 and 3.2 on the 5 point scale where 1 = no difference and 5 = very large difference. In 3 out of 5 plants, the CA + PGA and low concentration PG treatment hams were not different (p > 0.05) from the blind control treatments. However the high PG treatment was not different (p > 0.05) from the control in 2 out of 5 plants (only in trial 1). In addition, the XG and low concentration PG treatment was only different (P > 0.05) from the blind control in 1 out of 5 plants in both trials. This indicates that the coatings did not impact the flavor in some of the plants but did impact the flavor in the other plants. This may have been due to differences among the plants in non-meat ingredients that were used, aging temperature and humidity, and aging time.For coating infused nets, the mite infestation tests showed that cubes wrapped with nets that were treated with coatings had significantly lower numbers of mites, varying from 3 to 62, after 2 wk, while cubes from the negative control and the positive control with untreated nets had up to 554 mites each. This demonstrates that the treated nets inhibited the reproduction of mites on hams, with some nets performing better than others.ConclusionThe food grade coatings may be applicable for some, but not all, processors. In addition, the coating infused ham nets demonstrate the potential to control mite infestations and should be scaled up for commercial testing.

Efficacy of selected food-safe compounds to prevent infestation of the ham mite, Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae), on southern dry-cured hams.

Tyrophagus putrescentiae (Schrank) is a serious mite pest of dried meats and cheeses. Infestations of T. putrescentiae are controlled with the fumigant methyl bromide, which is an ozone-depleting substance and is currently being banned in most countries. Effective alternatives to methyl bromide are needed. The objective of this research was to use laboratory assays to investigate the effectiveness of food-safe compounds for preventing infestation of T. putrescentiae on dry-cured hams. Ham pieces dipped in solutions of either propylene glycol (1,2-propanediol), lard, ethoxyquin or butylated hydroxytoluene prevented or significantly reduced mite population growth. Behavioral assays revealed that more mites oriented to the untreated control ham cubes, and more eggs were laid on these untreated ham cubes, compared with cubes treated with various dips. Our results also indicated that a combination of carrageenan + propylene glycol alginate + 40% propylene glycol was effective in reducing mite numbers on whole aging hams compared with untreated whole hams. Several food-safe compounds can prevent infestation of T. putrescentiae on dry-cured hams and may represent alternatives for managing this pest. © 2015 Society of Chemical Industry.

Influence of Mastication on Gastric Emptying

The role of mastication on digestion efficiency remains to be demonstrated. This study investigates whether masticatory function influences gastric emptying rate. Twelve normal volunteers were studied on two occasions after ingestion of the same test meal containing ham cubes, crackers, and egg (mixed with 13C-octanoic acid), chewed, in random order, either with 50 masticatory cycles or with 25 cycles, swallowing ham cubes whole. Lag phase (Tlag) and gastric half-emptying time (T1/2) were measured by means of the 13C-octanoic acid breath test. Trituration performance was assessed by the sieve test, and was expressed as the percentage of ham particles < or = 1 mm after 50 masticatory cycles. Tlag and T1/2 were significantly shorter when the meal was chewed with 50 cycles than with 25 cycles (Tlag 25.9+/-3.8 vs. 36.4+/-4.1 min, p=0.017; T1/2 49.1+/-5.7 vs. 62.5+/-6 min, p=0.009). Trituration performance was inversely related to both Tlag (r=0.621, p=0.031) and T1/2 (r=0.699, p=0.012). Comminution of food influences significantly gastric emptying rates.