Dry-cured hams often become infested with ham mites (Tyrophagus putrescentiae) during the aging process. Methyl bromide has been used to fumigate dry cured ham processing plants and is the only known fumigant that is effective at controlling ham mite infestations. However, methyl bromide will be phased out of all industries by 2015. This research was designed to 1) determine the efficacy of phosphine fumigation at controlling ham mites and red-legged beetles and its impact on the sensory quality and safety of dry cured hams, and 2) to develop and evaluate the potential of using food-grade film coatings to control mite infestations without affecting the aging process or sensory properties of dry-cured hams. Fumigation trials were conducted in simulated ham aging houses and commercial ham aging houses. Mite postembryonic mortality was 99.8% in the simulated aging houses and >99.9% in commercial aging houses two weeks post fumigation. Sensory tests with trained panelists indicated that there were no detectable differences (P>0.05) between phosphine fumigated and control hams. An analytical method was developed to determine phosphine concentration in ham. In addition, residual phosphine concentration was below the legal limit of 0.01 ppm in ham slices taken from phosphine fumigated hams. Coating trials were conducted on ham cubes and slices. Cubes coated with xanthan gum+20% propylene glycol and carrageenan/propylene glycol alginate+10% propylene glycol were effective at controlling mite infestations under laboratory conditions. Barrier properties (water vapor permeability and oxygen permeability) were measured to estimate the impact of coatings during the aging process. It was evident that carrageenan/propylene glycol alginate were permeable to moisture and therefore could potentially be applied to the hams during the aging process.

Since methyl bromide is an ozone depleting substance, there is a significant need to find effective alternative compounds 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 to minimize mite reproduction and mold growth on dry cured hams in untreated and food grade ingredient infused nets. Mites on ham slices in untreated nets were reduced from the initial inoculum level of 50 mites per ham slice when exposed to 85% RH at 24, 28, and 32°C. Results indicated that hams should be stored at 85% RH or greater to minimize mite reproduction when xanthan gum and propylene glycol infused nets are used. Nets infused with carrageenan, propylene glycol alginate, and propylene glycol, completely inhibited mite reproduction at 85% RH and were effective at controlling mold growth.

Randomized complete block designs with three replications were utilized to evaluate the effects of fumigation with sulfuryl fluoride (SF) (0, 12, 24, 36 and 72 mg/L), phosphine (PH3) (0, 200 and 1000 ppm at 48 hr), methyl bromide (MB) (0, 4, 8, 16, and 32 mg/L for 48 hr), carbon dioxide (CO2) (0, 60% at 48 hr and 60% at 96 hr) and ozone (O3) (0 ppm and 175 ppm for 48 hr) on the 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. Also, as phosphine fumigation concentration increased, the residual concentration of phosphine also increased in the hams (P < 0.05), but all samples contained levels that were lower than the legal limit of phosphine in stored food products (0.01 ppm). Minimal differences existed in the presence and concentration of aroma active compounds in fumigated hams when compared to the control. Triangle tests indicated that consumers could not discern (P > 0.75) between the control hams and the fumigated hams. This study revealed that there were minimal aroma/flavor differences among control hams and hams that were fumigated with SF, PH3, MB, CO2 or O3 and that fumigation of dry cured ham with SF and PH3 were safe and met legal requirements for consumption. This reveals that SF, PH3, CO2 and O3 could be tested at the industrial level to determine their efficacy as potential alternatives to methyl bromide to treat dry cured hams for insect pests.

Le coproduit de fabrication de jambon sec est issu de l'opération de désossage de la cuisse de porc parée, salée, séchée et affinée. Il est constitué à plus de 85 % d'os et de tissus associés (cartilages, ligaments, tendons). Le concassage au broyeur à marteau permet d'homogénéiser le coproduit en morceaux de taille inférieure à 8 cm (> 90 % compris entre 40 et 80 mm). La composition chimique de la matière sèche du mélange (77 ± 3 % de MS) est de 33 ± 5 % en protéines (89 % de collagène, 14 % de protéines hydrosolubles, 6 % d'acide aminés libres), 31 ± 3 % en lipides (triglycérides : 70 % ; diglycérides : 3,5 % ; acides gras libres : 11 % ; saturé/insaturé : 0,87 ; 24 % C16 :0 ; 13 % C18 :0 ; 2 % C16 :1 ; 38 % C18 :1 ; 4 % C18 :2) et 26 ± 4 % de matière minérale (phosphate de calcium 88 % ; NaCl 9 %). L'extraction aqueuse des lipides et des protéines du coproduit est étudiée en contacteur agité. Le raffinat solide est séparé par filtration à chaud sous forme de granulat et la matière grasse entraînée est séparée par décantation à froid. L'étude de l'influence des principaux facteurs de l'extraction liquide/solide (temps de contact : 30 à 90 min, température : 40 à 90°C ; ratio eau/coproduit : 4 à 10) grâce à la réalisation d'un plan d'expérience met en évidence les effets de la solubilisation et la coagulation des protéines sur l'entraînement des lipides et leur décantation sous forme de matière grasse. Mis en oeuvre à l'échelle pilote (64 kg de coproduit de jambon sec concassé, 207 kg d'eau, 30 min à 90°C en contacteur agité), le procédé de fractionnement aqueux conduit par filtration centrifuge et séchage à un granulat stable (rendement : 59 % ; matière minérale : 41 % ; protéines : 43 % ; lipides : 16 %), source de phosphate de calcium (95 % de la matière minérale) et de gélatine ou de colle d'os (88 % de protéines de nature collagénique). La fraction matière grasse décantée (rendement : 24 % ; lipides : 93 % ; triglycérides : 75 % ; diglycérides : 4 % ; acides gras libres : 7 % ; saturé/insaturé : 0,82 % ; 37 % C16 :0 ; 15 % C18 :0 ; 2 % C16 :1 ; 44 % C18 :1 ; 8 % C18 :2) présente les mêmes caractéristiques physicochimiques que le saindoux, avec une odeur proche de celle du jambon sec (19 COV aromatiques identifiés présents dans les arômes majoritaires de jambon). La fraction protéines solubilisées, obtenue sous forme de lyophilisat après concentration de la phase aqueuse (rendement : 8 % ; protéines : 52 % dont 29 % d'acides aminés libres ; matière minérale : 29 % dont 90 % NaCl, lipides : 3 %), contient aussi des glucosaminoglycanes sulfatés (GAGs : 3,4 %). Ces caractéristiques de composition, associées à ses propriétés épaississantes et gélifiantes, adhésives et stabilisantes d'émulsion, font de cette fraction minoritaire du procédé de fractionnement aqueux du coproduit de jambon sec, un extrait aux multiples applications à forte valeur ajoutée (source de peptones pour la culture de champignons et de levures, adhésif et liant naturel, ingrédient de formulation alimentaire nutracétique et cosmétique). / The ham production by-product comes from the deboning of dressed, salted, dried and refined pork leg. It consists of more than 85% of bone and associated tissues (cartilage, ligaments, tendons). Hammer mill crushing allows homogenizing the by-product into pieces smaller than 8 cm (> 90% between 40 and 80 mm).Dry matter chemical composition of the blend; (77 ± 3% DM) is 33 ± 5% protein (89% collagen, 14% of watersoluble proteins, 6% free amino acid), 31 ± 3% lipids (triglycerides: 70% diglycerides: 3.5%; free fatty acids: 11%; saturated / unsaturated: 0.87; 24% C16: 0; 13% C18: 0; 2% C16: 1; 38% C18: 1; 4% C18: 2) and 26 ± 4% mineral matter (calcium phosphate 88%, 9% NaCl). Lipids and proteins aqueous extraction of the by-product is studied in an agitated contactor reactor. The solid raffinate was separated by hot filtration to an aggregate and the fat is separated by cold decantation.The study of the influence of main factors of the liquid / solid extraction (contact time: 30 to 90 min, temperature: 40 to 90 °C; ratio water / by-product: 4 to 10) through the implementation of an experimental design, highlights the effects of proteins dissolution and coagulation on lipid output and decantation as fat matter.By pilot scale implementation (64 kg of crushed by-product of dry-cured ham, 207 kg of water, 30 min at 90 ° C in agitated contactor), the aqueous fractionation process leads, by centrifugal filtration and drying, to a stable aggregate (yield: 59%; mineral matter: 41%; protein 43%; lipids: 16%), source of calcium phosphate (95% of the mineral) and gelatin or bone glue (88% collagenous protein).The decanted fat fraction (yield: 24%; lipids: 93%; triglycerides: 75%; diglycerides: 4% free fatty acids: 7%; saturated / unsaturated: 0.82%; 37% C16: 0; 15% C18: 0; 2% C16: 1; 44% C18: 1; 8% C18: 2) has the same physicochemical characteristics as lard, with an odor similar to that of dry-cured ham (19 identified aromatic VOC part of ham main flavors). The solubilized protein fraction, obtained as a lyophilized extract after concentration of the aqueous phase (yield: 8%; protein: 52% with 29% of free amino acids; mineral matter: 29%, with 90% NaCl, lipids: 3%), also contains sulfated glycosaminoglycans (GAGs: 3.4%). These composition characteristics, associated with its thickening and gelling properties, adhesive and stabilizing for emulsion, transforms this minor fraction of the aqueous fractionation process of the dry-cured ham byproduct, in an high added value multiple applications extract (source of peptones for culture for fungi and yeasts, a natural and binding adhesive, ingredient for food nutraceutic and cosmetic formulation).

Doctor of Philosophy / Department of Entomology / Thomas W. Phillips / Robert "Jeff" J. Whitworth / Dry-cured ham is protected from infestations of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) with the fumigant methyl bromide. Developing feasible alternatives to methyl bromide is necessary due to the phase out of methyl bromide. The effectiveness of food-safe compounds for preventing infestations of T. putrescentiae on dry-cured hams was evaluated by dipping ham pieces in solutions of various food additives. Propylene glycol (1, 2-propanediol), lard, ethoxyquin and butylated hydroxytoluene prevented or significantly reduced mite population growth. A combination of carrageenan + propylene glycol alginate + 40% propylene glycol was effective in reducing mite numbers on treated whole-aged hams compared with untreated hams. Dose/response tests with twelve registered residual insecticides were conducted to assess contact toxicity to T. putrescentiae. Three of these insecticides were evaluated for persistence over a 2-month period on different surfaces. Commercial formulations of deltamethrin plus chlorpyrifos-methyl, chlorfenapyr, and malathion showed promising results for contact toxicity against T. putriscentiae. Chlorfenapyr applied to metal, concrete, and wood resulted in 100% mortality of treated ham mites for up to 8 weeks. The effect of high and low temperatures on mortality of T. putrescentiae was studied in the laboratory. Groups of 10 eggs and groups of a mixture of 40 adults and nymphs were separately exposed to several high and low temperatures, ranging from +35 to 45°C and from −20 to +5°C, for several time periods. Eggs were found to be more tolerant to both high and low temperatures compared with adults and nymphs. Results showed that high temperatures from 40-45°C killed all T. putrescentiae eggs, adults, and nymphs within 4-1 d, while −10°C or lower killed all the same stages in less than 1 d. Combinations of the fumigant sulfuryl fluoride (SF) applied under high temperatures ranging from 25-40ºC, were studied to determine the highest temperature, shortest exposure time, and the lowest value of a concentration-by-time product (CTP) of SF against T. putrescentiae. Results showed that complete control of all life stages of T. putrescentiae was achieved at 40ºC with SF. More than one day of exposure was required to kill adults and nymphs and eggs at 40ºC at a CTP close to the EPA labeled rate of 1500 gh.m⁻³. Results indicated that adults and nymphs were more susceptible to SF compared to eggs. This study focused on investigating different control methods for T. putrescentiae in dry-cured ham facilities and most of examined techniques are preventive, although some of them can be applied as remedial methods after mite infestations are noticed.

Escherichia (E.) coli O157:H7 survival in dry cured (uncooked) meat products leading to human illness outbreaks is an international problem. Their manufacture does not involve a heat kill step to ensure the destruction of the organism, and the adverse conditions created during processing may not be sufficient to prevent E. coli O157:H7 survival. Deodorized yellow mustard powder has antimicrobial properties from glucosinolate (sinalbin) hydrolysis catalyzed by the endogenous enzyme myrosinase, generating antimicrobial isothiocyanate (PHBIT). Previous work has shown that its addition during dry sausage manufacture was capable of eliminating the pathogen. In this study, its use for the same purpose was investigated during dry cured Westphalian ham production. Hams were inoculated with a 7.5 log cfu•g-1 cocktail of E. coli O157:H7, surface applied with 4% or 6% (w/w) deodorized yellow mustard powder, and monitored for E. coli O157:H7 survival during 80d ham maturation. One trial included the inoculation of Staphylococcus (S.) carnosus, a meat starter culture with myrosinase-like activity, onto the hams (after salt equilibration) to accelerate formation of antimicrobial isothiocyanate from mustard glucosinolate and help control the pathogen. In both trials, E. coli O157:H7 was reduced 3 log cfu•g-1 by 21d on hams treated with mustard powder, whereas only a 1 log cfu•g-1 reduction was found in the inoculated control which was not treated with mustard. By 45d, hams treated with mustard powder showed a reduction of >5 log cfu•g-1 E. coli O157:H7, whereas it took 80d to for numbers in control hams to be similarly reduced. Since a 5 log kill of E. coli O157:H7 was achieved in control hams by the end of 80d, dry cured Westphalian ham manufacture would be considered capable of controlling the risk of E. coli O157:H7 survival by North American regulatory agencies. However, deodorized yellow mustard powder at 4%, and to a greater extent at 6%, eliminated the pathogen at a significantly faster rate than the control during ham processing. Addition of the S. carnosus starter culture in trial 2 may have contributed to the maintenance of this effect through isothiocyanate formation. It also helped restore numbers of staphylococci, which were found to be sensitive to deodorized mustard powder.

Escherichia (E.) coli O157:H7 survival in dry cured (uncooked) meat products leading to human illness outbreaks is an international problem. Their manufacture does not involve a heat kill step to ensure the destruction of the organism, and the adverse conditions created during processing may not be sufficient to prevent E. coli O157:H7 survival. Deodorized yellow mustard powder has antimicrobial properties from glucosinolate (sinalbin) hydrolysis catalyzed by the endogenous enzyme myrosinase, generating antimicrobial isothiocyanate (PHBIT). Previous work has shown that its addition during dry sausage manufacture was capable of eliminating the pathogen. In this study, its use for the same purpose was investigated during dry cured Westphalian ham production. Hams were inoculated with a 7.5 log cfu•g-1 cocktail of E. coli O157:H7, surface applied with 4% or 6% (w/w) deodorized yellow mustard powder, and monitored for E. coli O157:H7 survival during 80d ham maturation. One trial included the inoculation of Staphylococcus (S.) carnosus, a meat starter culture with myrosinase-like activity, onto the hams (after salt equilibration) to accelerate formation of antimicrobial isothiocyanate from mustard glucosinolate and help control the pathogen. In both trials, E. coli O157:H7 was reduced 3 log cfu•g-1 by 21d on hams treated with mustard powder, whereas only a 1 log cfu•g-1 reduction was found in the inoculated control which was not treated with mustard. By 45d, hams treated with mustard powder showed a reduction of >5 log cfu•g-1 E. coli O157:H7, whereas it took 80d to for numbers in control hams to be similarly reduced. Since a 5 log kill of E. coli O157:H7 was achieved in control hams by the end of 80d, dry cured Westphalian ham manufacture would be considered capable of controlling the risk of E. coli O157:H7 survival by North American regulatory agencies. However, deodorized yellow mustard powder at 4%, and to a greater extent at 6%, eliminated the pathogen at a significantly faster rate than the control during ham processing. Addition of the S. carnosus starter culture in trial 2 may have contributed to the maintenance of this effect through isothiocyanate formation. It also helped restore numbers of staphylococci, which were found to be sensitive to deodorized mustard powder.

Doctor of Philosophy / Department of Entomology / Thomas W. Phillips / The phase-out of methyl bromide production, the most effective fumigant for the control of the ham mite, Tyrophagus putrescentiae (Schrank) (Acari: Acaridae), on dry-cured ham has necessitated the search for other management methods. The foundation of a successful management program is an effective monitoring program that provides information on pest presence and abundance over time and space to help in making management decisions. By using the standard trap made from disposable Petri dishes and a dog food-based bait, mite activity was monitored weekly in five dry-cured ham aging rooms from three commercial processing facilities from June 2012 to September 2013. Results indicated that mite numbers in traps in facilities typically had a pattern of sharp decline after fumigation, followed by a steady increase until the next fumigation. Average trap captures varied due to trap location, indicating that traps could be used to identify locations where mite infestation of hams may be more likely to occur. Experiments were also conducted in 6 m x 3 m climate-controlled rooms to determine the effects of some physical factors on trap capture. Factors such as trap design, trap location, trap distance, duration of trapping, and light conditions had significant effects on mite capture. Mites also responded differently to light emitting diodes of different wavelengths, either as a component of the standard trap or as a stand-alone stimulus to orientation. To determine the relationship between trap capture and mite density, experiments were carried out in the climate-controlled rooms. Mite density was varied but trap number remained constant for all mite densities. There was strong positive correlation between trap capture and mite density. In simulated ham aging rooms, the distribution of mites on hams was determined and different sampling techniques such as vacuum sampling, trapping, rack sampling, ham sampling and absolute mite counts from whole hams were compared and correlated. Results showed weak or moderate correlations between sampling techniques in pairwise comparisons. Two sampling plans were developed to determine the number of samples required to estimate mite density on ham with respect to fixed precision levels or to an action threshold for making pest management decisions. Findings reported here can help in the optimization of trapping and sampling of ham mite populations to help in the development of efficient, cost-effective tools for pest management decisions incorporated with alternatives to methyl bromide.

Orientador: Pedro Eduardo de Felicio, Expedito Tadeu Facco Silveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T13:59:07Z (GMT). No. of bitstreams: 1 BergaminFilho_Walter_M.pdf: 465962 bytes, checksum: 7133c03c01d649f1e25c78b4b0f9e052 (MD5) Previous issue date: 2005 / Resumo: A metodologia de elaboração de presunto cru proposta neste trabalho foi planejada com base na combinação de desossa, adição de transglutaminase, massageamento e moldagem das peças previamente à secagem e maturação. Analisaram-se os efeitos de dois teores de NaCl adicionado (3,5% e 5% do peso da carne) nas propriedades físico-químicas do produto final, como Aw, teor de cloretos (NaCl%) e de umidade, e perda de peso. Como nos processos tradicionais, fez-se a salga seca utilizando nitrato de sódio, nitrito de sódio e sal grosso comercial tipo I. As médias de temperatura (T) e umidade relativa (UR) desta etapa ficaram em torno de 2,5 ± 1,31ºC e 83 ± 2,75%, respectivamente. Já na etapa de secagem, houve redução da UR média para 71,62 ± 1,75% e aumento da T média para 4,5 ± 0,85ºC. Na maturação, as temperaturas foram acrescidas de 1ºC a cada nove (ou sete) dias, até atingir 16ºC, enquanto a UR foi mantida em ±70%. Ao final do processo, os presuntos crus apresentaram as seguintes características físico-químicas: Aw no centro da peça de 0,900 e 0,905, para os tratamentos 3,5% e 5% de sal, respectivamente; para os teores de umidade, não houve diferença significativa, porém, o tratamento 5% apresentou um valor de 53,04 ± 2,37%, superior ao do tratamento 3,5%, que foi de 48,65 ± 2,76%. Este último parâmetro é conseqüência da perda de peso dos presuntos durante todo o processo, que foi significativamente maior no tratamento 3,5%, atingindo 39,74 ± 4,02%, contra os 37,22 ± 2,96% do tratamento 5%. O curto período de maturação e as temperaturas amenas durante esta fase, retardaram a ação enzimática responsável pela hidrólise de aminoácidos, provocando a queda do pH final, que atingiu valores de 5,60 e 5,56 para os tratamentos 3,5 e 5% de sal, respectivamente. Quanto às características microbiológicas, ambos os tratamentos estavam de acordo com a legislação vigente no país. Os presuntos crus obtidos no término do processo apresentaram formato e espessura apropriados para o fatiamento, excelente aparência, aroma característico e principalmente, um sabor muito próximo ao dos presuntos crus tradicionais encontrados no mercado brasileiro / Abstract: The methodology proposed to produce the dry-cured ham in this work was based on a technology combining bonning, transglutaminase application, tumbling and molding. It was evaluated the effects of two levels of NaCl added for fresh meat (3.5 and 5%) on the physicochemical characteristics of the final products such as water activity (Aw), chloride content (NaCl%) and weight loss. Similar to the traditional processing of dry cured hams, salting was carried out using dry cure, combining NaCl, sodium nitrate and sodium nitrite. The average temperature (T) and relative humidity (RH) in this phase were 2,5 ± 1,31ºC and 83 ± 2,75%, respectively. In the drying period, the average RH was reduced to 71,62 ± 1,75% and average T was increased up to 4,5 ± 0,85ºC. During the ageing, the T was increased gradually 1ºC each nine (or seven) days up to 16ºC, while the RH was fixed to ± 70%. At the end of the processing time, the dry cured hams presented: Aw values 0.900 and 0.905, measured in the inner part of the product for the treatments 3.5% and 5%, respectively. Treatment 5% presented higher values (53.04 ± 2.37%) of moisture than the 3.5% (48.65 ± 2.76%). This last parameter was a consequence of the weight loss during the processing time, that where higher in the treatment 3.5% (39.74 ± 4.02%) than the 5% (37.22 ± 2.96%). The mild temperatures during the short ageing time have possibly decreased the amino acids hydrolysis, and this the probable cause of the final pH, which were 5.60 and 5.56 for the treatments 3.5 and 5%, respectively. In the microbiological counts, both treatments satisfy the Brazilian current legislation requirement. The dry cured hams at the end of the processing presented shape and thickness appropriate to slicing, excellent appearance, characteristic aroma, and mainly, similar flavor to the traditional dry cured hams found in the Brazilian market / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos

Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae), also known as the ham mite, may infest dry cured hams during the aging process. The fumigant methyl bromide is currently used to control mite infestations, but eventually will 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, propylene glycol (PG), and lard were evaluated for their impact on mite orientation to or oviposition on treated or untreated ham cubes, mite reproduction and population growth over a 10-week period. When nets were infused with gum and PG, behavioral tests indicated that greater 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 indicated that there were fewer (P < 0.05) T. putrescentiae produced over a two-week period on ham cubes covered with both gum and PG treated nets when compared to the untreated or gum-only treated nets over the 10-week storage period of the experiment. Medium and high concentrations of PG treatments had the lowest mite reproduction rates. No more than four mites could be found on each of these treatments in comparison to 200-300 mites that were on the untreated ham cubes. When nets were infused with gum, PG, and lard, behavioral tests indicated that fewer mites oriented to the ham cubes that were wrapped with gum, lard, and medium PG than those with untreated nets. The oviposition assays revealed that on average less than three eggs were laid on the ham cubes with treated nets in comparison to 69-165 eggs on the untreated ham cubes. Reproduction assays demonstrated that fewer T. putrescentiae (P < 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 weeks of storage. Lard infused nets without PG did not decrease the mite population (P > 0.05). The net without coating slowed the growth and reproduction of T. putrescentiae since net controls had fewer mites (P < 0.05) than controls without nets. With a few exceptions, fungi were not present on ham cubes that were treated with PG-containing nets over 10 weeks of storage. This research demonstrated the efficacy of using 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.