Sulfuryl fluoride fumigation effects on the safety,volatile composition,and sensory quality of dry cured ham

A randomized complete block design with three replications was utilized to evaluate the effects (P < 0.05) of various fumigation concentrations of sulfuryl fluoride (SF) (0, 12, 24, 36 and 72 mg/L) on the fluoride, sulfuryl fluoride, and volatile flavor compound concentrations in dry cured ham. Fluoride and SF concentrations increased (P < 0.05) in dry cured hams as SF fumigation concentration increased, but all samples contained fluoride and SF concentrations below the legal limits of 20 and 0.01 ppm, respectively. Minimal differences existed (P > 0.05) in the presence and concentration of aroma active compounds, but oxidation compounds were slightly more prevalent (P < 0.05) in the 72 mg/ml treatment when compared to the control. A triangle test (n = 54) indicated that consumers could not discern (P > 0.75) between hams that were fumigated with SF at 0 and 36 mg/ml. This study revealed that there were minimal aroma/flavor differences among the ham treatments between 0 and 36 mg/ml, and that dry cured ham that was fumigated with SF was safe and met legal requirements for consumption.     

Effects of Carbon Dioxide and Ozone Treatments on the Volatile Composition and Sensory Quality of Dry-Cured Ham

Abstract: Randomized complete block designs with 3 replications were utilized to evaluate the effects of carbon dioxide (CO₂) (0% at 96 h, 60% at 48 h, and 60% at 96 h) and ozone (O₃) (0 and 175 ppm for 48 h) on the volatile flavor compound concentrations in dry-cured ham. Minimal differences existed in the presence and concentration of aroma active compounds in both CO₂ and O₃ fumigated hams but phenols were slightly more prevalent (P < 0.05) in the CO₂ treatments and oxidation compounds were slightly elevated (P < 0.05) in the ozone treated samples when compared to the control. Triangle tests (n = 54 and 56) indicated that consumers could not discern (P > 0.75) between the control hams and the hams that were fumigated with CO₂ and O₃, respectively. This study revealed that there were minimal aroma/flavor differences among the ham treatments between 0 and 60% CO₂ for 96 h; and also between 0 and 175 ppm O₃.     

Penetration of methyl bromide, sulfuryl fluoride, ethanedinitrile and phosphine into timber blocks and the sorption rate of the fumigants

To evaluate timber fumigants alternative to the ozone-depleting methyl bromide (MB), pinewood (Oregon, Pseudotsuga menziesii) blocks (10 cm × 10 cm × 30 cm) were fumigated in a stainless steel chamber (30.0 L). The timber blocks were fumigated at 48 mg L⁻¹ of MB, sulfuryl fluoride (SF) and ethanedinitrile (C₂N₂) and 1 mg L⁻¹ of phosphine (PH₃) for 48 h. During fumigation, 70% MB, 35% SF, 63% C₂N₂ and 25% PH₃ were absorbed by the timber block. At 6-h exposure, the concentrations of SF, PH₃ and C₂N₂ in the headspace of the chamber were stable. Each fumigant penetrated to all parts of the block, but the speed and extent of penetration were different. The fumigants that most rapidly achieved an even concentration throughout the block and chamber were PH₃ and C₂N_2. The maximum variation of MB, SF, C₂N₂ and PH₃ concentration between the chamber and gas port (15 cm) was 81.3, 11.8, 1.5 and 9.3% at 24-h exposure and 76.8, 9.3, 0.5 and 1.1% at 48-h exposure respectively. Possible alternative fumigants to MB need to penetrate timber at least as well as MB; SF, PH₃ and C₂N₂ met this criterion.     

Qualitative effects of fresh and dried plum ingredients on vacuum-packaged,sliced hams

Boneless ham muscles (Semimembranosus + Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at <4 °C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo–Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P < 0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P < 0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P > 0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments.     

Quality characteristics of chunked and formed hams from pale,average and dark muscles were improved using an ammonium hydroxide curing solution

Cooking yield, cooked pH, purge loss, moisture, lipid oxidation, external and internal color, break strength and elongation distance were assessed for pale (PALE), average (AVG) and dark (DARK) inside hams injected with either a control cure solution (CON) or BPI-processing technology cure solution (BPT). Following enhancement, muscles were chunked, vacuum tumbled, smoked and cooked to 66 °C. Cooked ham pH was 6.49 for DARK, 6.40 for AVG, and 6.30 for PALE, respectively (P < 0.0001). Cooked pH was higher (P < .0001) for BPT than CON. Cooked ham moisture content was higher (P < 0.0001) for BPT hams than CON hams (74.83 vs. 74.11%) but BPT did not significantly influence cooking yield or lipid oxidation. Consumers (n = 150) of diverse demographics rated hams for appearance and taste. Results indicated that BPI-processing technology improved visual appearance of hams made from pale, average, and dark muscles and improved the eating quality of hams made from pale muscles.     

Phosphine resistance in stored-product insects collected from various grain storage facilities in Morocco

Despite heavy dependence on phosphine (PH₃) for fumigating stored products, the resistance status of insect pests in Morocco has never undergone a thorough investigation. Some control failures with PH₃ were reported in Morocco, and a previous study showed two field populations of Sitophilus oryzae to be highly resistant to phosphine.We surveyed phosphine resistance in field populations of three major insect pests of stored wheat in Morocco. Around 32% of the samples collected at different storage facilities were found to be infested with one or more species of stored-product beetles. First-generation adult beetles, cultured from the field samples, were subjected to a discriminating dose test for phosphine resistance using an FAO method. The results indicated that, with the exception of one population of S. oryzae, all samples tested contained phosphine-resistant individuals. Treatments at up to 1.8 g m⁻³ of phosphine for 20 h, or at 0.18 g m⁻³ for up to 5 days, indicated that a high degree of resistance was already selected in some of the insect populations.Tests using [³²P]-radiolabelled phosphine showed that the mechanism of resistance in the three insect species tested involved a reduced uptake of the fumigant. The study has highlighted an urgent need for reviewing current fumigation practices in Morocco to ensure effective use of phosphine and avoid further selection of resistance.     

Carcass and ham quality characteristics of heavy pigs from different genetic groups intended for the production of dry-cured hams

Carcass and ham quality characteristics of pig populations divided by harvest weights — HW (130 and 160 kg) were evaluated to determine the effects of gender (barrows and gilts) and distinct genetic groups — purebred (DUDU) and crossbred Duroc (DULA, DUWI and DULL) as well as purebred Large White (WIWI) on the suitability for use in dry-cured ham production. At 130 kg, DUDU pigs yielded the highest fat thickness of the ham (P < 0.01) and an intramuscular fat content (IMF) of 3.15% in Semimembranosus muscle (SM). DUDU pigs also had a SM pH_u of 5.7. This genetic group met the specifications for dry-cured ham production. No differences could be found in meat quality characteristics between genetic groups harvested at 160 kg. However at this HW, gilts produced significantly (P < 0.05) heavier and leaner hams compared to barrows.     

Sulfuryl fluoride as a methyl bromide alternative for fumigation of Necrobia rufipes (Coleoptera: Cleridae) and Tyrophagus putrescentiae (Sarcoptiformes: Acaridae), major pests of animal-based stored products

Sulfuryl fluoride (SF) has been registered in many countries for stored product applications as an alternative to other fumigants, especially methyl bromide (MB). Research was conducted to establish SF fumigation protocols for the mortality of pests infesting post-harvest durable commodities. The efficacy of SF against two major arthropod pests of southern dry-cured hams, the red-legged ham beetle, Necrobia rufipes, and the ham mite, Tyrophagus putrescentiae, was investigated. SF caused significant mortality in ham beetles but not for ham mites when treated for 48 h at 23 °C. Eggs of N. rufipes were more tolerant to SF than other stages fumigated. In addition, early aged (1–2 d old) eggs of N. rufipes were more susceptible to SF than late-aged (4–5 d old) eggs. Furthermore, SF fumigation led to 100% control of larvae, pupae and adults of N. rufipes by 8 g/m³ while the eggs required 20.88–24.72 g/m³ to prevent 100% hatch. However, T. putrescentiae showed high tolerance to SF as it survived concentration-time products in excess of the standard label limit 1500 g h/m³. SF studies also revealed that the eggs of T. putrescentiae were several fold more tolerant than that of the mobile stage, the nymphs and adults. SF trials under pilot-scale commercial conditions were also carried out that further supported the efficacy of SF for red-legged ham beetles but not for the ham mite. SF may not be suitable for managing ham mites based on work to date, but future work could investigate longer exposure times at higher temperatures.     

A note on the relationships between cured-cooked and dry-cured ham processing yields

Right and left hams from 353 pigs slaughtered at around 100 kg body weight were processed into cured-cooked hams and dry-cured hams, respectively. Weights and yields at various stages of each process, carcass lean content and fresh meat quality traits were registered. Technological yield of cured-cooked processing (saleable cooked ham weight/defatted–deboned fresh ham weight) was more closely correlated to ultimate pH (r = 0.51, p < 0.001) than to carcass leanness (r = −0.13, p < 0.05) whereas the reverse situation – r = 0.15 (p < 0.01) and r = −0.62 (p < 0.001), respectively – was found for technological yield of dry-cured processing (saleable dry ham weight/trimmed fresh ham weight). The correlation between the two technological yields was significantly positive but of fairly moderate magnitude (r = 0.36). The correlation between the overall yields (saleable processed ham weight/entire fresh ham weight) of the two processes revealed to be very close to zero (r = −0.01).     

Use of Magnetic Resonance Imaging for monitoring Parma dry-cured ham processing

Protocols were developed to apply Magnetic Resonance Imaging (MRI) to the dry-curing of Italian Parma ham. NMR relaxation analyses were performed on dry-cured hams at different processing stages to evaluate the ranges of variation of ¹H relaxation times T₁ and T₂ in representative ham muscle tissues, due to dehydration and salt uptake. MRI maps of the same ham sections were acquired, allowing T₁ and T₂ average values to be computed in selected Regions of Interest (ROI) inside muscle Semimembranosus, Semitendinosus and Biceps femoris. Chloride and moisture were determined by conventional chemical methods on the same ROIs, and MRI T₁ and T₁/T₂ ratio were selected in a model (R² = 0.90, P < 0.05) fitting the salt content of the analysed muscle cores. Short Time Inversion Recovery (STIR) sequences were also applied to green and cured hams, but on fresh samples only, a bright image, displaying a clear separation between lean and fat tissue, was obtained.     

Vitamin (B1, B2, B3 and B6) content and oxidative stability of Gastrocnemius muscle from dry-cured hams elaborated with different nitrifying salt contents and by two ageing times

The effect of the amount of added nitrate and nitrate plus nitrite to dry-cured hams on the vitamin (B1, B2, B3, B6) content, the antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) activities and the thiobarbituric acid reactive substances (TBARS) was assessed in Gastrocnemius muscle at the end of two ripening processes. Five different curing mixtures (Hi–N: 600 KNO₃; Lo–N: 150 KNO₃; Hi–Mix: 600 KNO₃ + 600 NaNO₂; Lo–Mix: 150 KNO₃ + 150 NaNO₂; Hi–Mix/Asc: 600 KNO₃ + 600 NaNO₂ + 500 sodium ascorbate, expressed as mg of salts added on surface per kg of fresh ham) were evaluated in dry-cured hams aged for 11.5 months (standard process, SP) and 22 months (long process, LP).     

Processing of dry-cured ham in a reduced-oxygen atmosphere: Effects on physicochemical and microbiological parameters and mite growth

The effects of a reduced-oxygen atmosphere (ROA) ([O₂] < 4.5%) during part or the whole of dry-cured ham processing on microbiological and physico-chemical parameters and mite growth were investigated in two independent experiments. In Experiment 1, six hams were processed in ROA and six in air for 275 days; in Experiment 2, where lower RH was used, six hams were processed in ROA for 289 days, six for 214 days in air + 75 days in ROA, and six in air for 289 days. Microbiological analyses during the process and physicochemical analyses in final products were carried out. The use of ROA during the whole process increased the L∗ colour parameter in the subcutaneous fat and proteolysis index and decreased b∗ in the external part of the subcutaneous fat and cholesterol oxide concentration. The use of ROA combined with low RH retarded microbial growth and prevented mite growth.     

Effect of phosphine on the respiration of adult Sitophilus zeamais Motsch. (Coleoptera,Curculionidae)

The relationship between mortality and oxygen uptake in adult Sitophilus zeamais treated with phosphine (PH₃) was investigated in order to clarify the mode of action of PH₃. When PH₃ was applied at concentrations of 5–20000 ppm to S. zeamais, the mortality of the insect did not increase as the concentration increased. High concentrations of PH₃ paralysed the insect in a way similar to a narcotic effect and decreased the respiratory rate. The amount of oxygen uptake during fumigation affected mortality, although uptake of PH₃ by the insect was not directly related to mortality.     

Quality attributes and color characteristics in three-piece boneless hams

One hundred and fifty hams were selected on visual assessment of quality into normal (C) and two-tone (TT) groups. CIE LAB color and pH measurements were collected at the plant 48 h postmortem on the gluteus medius (GM), gluteus profundus (GP), and rectus femoris (RF), and again at 72 h on the semimembranosus (SM), biceps femoris (BF), semitendinosus (ST), and RF. Data were analyzed using GLM procedures of SAS, and correlations between color scores, pH, and drip loss were calculated. Plant and fabrication pH were lower (P < 0.01) in GM from TT hams compared with C. Muscles from TT hams had lower (P < 0.01) L* and a* values compared with C. The GM L* and GM pH values were correlated (P < 0.05) with L* values for all other muscles and drip loss in SM. These data show that GM color and pH are accurate predictors of pork quality attributes in the muscles of a three-piece boneless ham.     

Influence of low-sodium mixtures of salts on the post-salting stage of dry-cured ham process

The reduction of added sodium chloride in dry-cured ham has been proposed to decrease the amount of sodium in the diet. The effect of substituting sodium chloride by potassium chloride, calcium chloride and magnesium chloride in some physicochemical characteristics of dry-cured ham throughout the post-salting stage was evaluated. The partial replacement of NaCl had significant effects on salt content at the end of the post-salting stage in the traditional process and this significantly affected a_w. The results showed that lower sodium hams, salted with a combination of NaCl and KCl, needed a maximum of 16 days more (32% increase) of post-salting than hams salted with 100% NaCl, while hams salted with a combination of NaCl, KCl, CaCl₂ and MgCl₂ needed a maximum of 26 days more (52% increase).     

High pressure effect on the color of minced cured restructured ham at different levels of drying, pH, and NaCl

Color changes of minced cured restructured ham was studied considering the effects of high pressure (HP) treatment (600 MPa, 13 °C, 5 min), raw meat pH₂₄ (low, normal, high), salt content (15, 30 g/kg), and drying (20%, 50% weight loss). Raw hams were selected based on pH₂₄ in Semimembranosus, mixed with additives, frozen, sliced, and dried using the Quick-Dry-Slice® process. Meat color (CIE 1976 L*a*b*) and reflectance spectra were measured before and after HP treatment. HP significantly increased L*, decreased a*, and decreased b* for restructured ham dried to 20% weight loss, regardless of salt content and pH₂₄. L* and a* were best preserved in high pH/high salt restructured ham. HP had no effect on the color of restructured ham dried to 50% weight loss. HP had no effect on the shape of reflectance curves, indicating that the pigment responsible for minced cured restructured ham color did not change due to HP.     

Creatine and creatinine evolution during the processing of dry-cured ham

Dry-curing of ham involves many biochemical reactions that depend on the processing conditions. The aim of this study was to evaluate the effect of the dry-cured processing on the concentration of creatine, creatinine and the creatinine/creatine ratio. Dry-cured hams under study were salted using three different salt mixtures (100% NaCl; NaCl and KCl at 50% each; and 55% NaCl, 25% KCl, 15% CaCl₂ and 5% MgCl₂) in order to observe its influence on creatinine formation but no significant differences were found between them at any time of processing. However, significant differences between different post-salting times (20, 50 and 80 days) and the ripened hams (7, 9 and 11 months of ripening) were observed. Results showed that creatine and creatinine remain stable once the ripening period is reached. These results were confirmed when analysing dry-cured ham samples submitted to extreme conditions of temperature and time (20, 30, 40 and 70 °C during 0, 20, 40 and 60 min) as well as commercial dry-cured hams with more than 12 months of processing.     

Reproduction of phosphine resistant Rhyzopertha dominica (F.) following sublethal exposure to phosphine

Phosphine fumigation is commonly used to disinfest grain of insect pests. In fumigations which allow insect survival the question of whether sublethal exposure to phosphine affects reproduction is important for predicting population recovery and the spread of resistance. Two laboratory experiments addressed this question using strongly phosphine resistant lesser grain borer, Rhyzopertha dominica (F.). Offspring production was examined in individual females which had been allowed to mate before being fumigated for 48 h at 0.25 mg L^?1. Surviving females produced offspring but at a reduced rate during a two-week period post fumigation compared to unfumigated controls. Cumulative fecundity of fumigated females from 4 weeks of oviposition post fumigation was 25% lower than the cumulative fecundity of unfumigated females. Mating potential post fumigation was examined when virgin adults (either or both sexes) were fumigated individually (48 h at 0.25 mg L^?1) and the survivors were allowed to mate and reproduce in wheat. All mating combinations produced offspring but production in the first week post fumigation was significantly suppressed compared to the unfumigated controls. Offspring suppression was greatest when both sexes were exposed to phosphine followed by the pairing of fumigated females with unfumigated males and the least suppression was observed when males only were fumigated. Cumulative fecundity from 4 weeks oviposition post fumigation of fumigated females paired with fumigated males was 17% lower than the fecundity of unfumigated adult pairings. Both of these experiments confirmed that sublethal exposure to phosphine can reduce fecundity in R. dominica.     

The effect of high pressure and residual oxygen on the color stability of minced cured restructured ham at different levels of drying,pH, and NaCl

Color stability of minced cured restructured ham was studied by considering the effects of high pressure (HP) (600 MPa, 13 °C, 5 min), raw meat pH₂₄ (low, normal, high), salt content (15, 30 g/kg), drying (20%, 50% weight loss), and residual oxygen level (0.02%–0.30%). Raw hams were selected by pH₂₄ in Semimembranosus, mixed with additives, frozen, sliced, and dried by the Quick-Dry-Slice® (QDS) process followed by HP treatment or not (control). Packaging and storage simulated industrial packaging: modified atmosphere containing 80% N₂, 20% CO₂, and residual O₂ in one of three intervals: < 0.1%, 0.1%–0.2%, or 0.2%–0.3%, and retail storage conditions: chill storage, 12 h light, 12 h darkness. HP improved the stability of the redness of 20% QDS hams, while the stabilizing effect on 50% QDS hams was smaller, concluding that water has the dominating role. Raw meat pH₂₄, salt content, and residual oxygen level had varying effects on the stability of the red color.     

Fumigation with essential oil of mustard retards fungal growth and accumulation of ergosterol and free fatty acid in stored shelled groundnuts

Shelled groundnut (Arachis hypogaea) samples with moisture contents (m.c.) between 7.5 and 10.5% and inoculated with conidia of Aspergillus glaucus and A. parasiticus were stored for 15-90 days at 25 ± 2 °C, and fumigated with synthetic food grade essential oil of mustard (100 μl/l space). Deterioration of the samples was assessed by estimating the percentage of kernels colonized by fungi, the number of colony forming units (CFUs)/kernel, and the accumulation of ergosterol and free fatty acids (FFA). The values of these variables increased with the m.c. and storage period, independent of the fumigation treatment; however, the rate of increase was significantly lower in fumigated samples. After 90 days storage, the proportion of kernels yielding A. glaucus was similar in all samples, but the number of CFUs was 300×, ergosterol content 3.6× and FFA 4× higher in non-fumigated than in fumigated samples. In fumigated samples, no molded kernels were visible, while many were seen in non-fumigated samples after 30 or 60 days storage at 10.5 or 9.3% m.c., respectively. The deterioration retardation featured a reduced inoculum on kernel surfaces. Aspergillus parasiticus did not colonize kernels independently of m.c. and fumigation treatments. There was a strong positive correlation between CFUs and ergosterol or FFA content when the data of fumigated and non-fumigated samples were analyzed separately. However, this relationship was absent when data were pooled to disregard the fumigation effect. The correlation between ergosterol and FFA content remained high regardless of the fumigation treatment (r = 0.99). The ergosterol or FFA content of stored groundnuts can be used interchangeably, as a sensitive indicator, to assess deterioration caused by xeric storage fungi. However, the latter was preferable because it was simpler to assess and provided a direct indication of economic losses due to reduced oil yield.