Sodium ascorbyl phosphate shows in vitro and in vivo efficacy in the prevention and treatment of acne vulgaris

Acne vulgaris is the most common inflammatory skin disorder and jeopardizes seriously the facial impression of a person. Development of acne involves a complex relation among several causes. Treatment and prevention success can be archived by affecting the main contributors positively like Proprionibacterium acnes or lipid oxidation leading to inflammatory reactions and follicular keratinization. Vitamin C tends to break down in cosmetic formulations resulting in a brownish discoloration. Sodium ascorbyl phosphate (SAP) represents a stable precursor of vitamin C that ensures a constant delivery of vitamin C into the skin. We were able to show that 1% SAP has a strong antimicrobial effect with a log reduction of 5 after 8 h on P. acnes in a time-kill study. Further on in a human in vivo study with 20 subjects an SAP O/W formulation significantly prevents the UVA-induced sebum oxidation up to 40%. Finally, we performed an open in vivo study with 60 subjects with a 5% SAP lotion over 12 weeks. The efficacy ranked as excellent and good of SAP was 76.9%, which was superior compared with a widely prescribed acne treatment. In conclusion, these data show that SAP is efficient in the prevention and treatment of acne vulgaris. SAP can be used in a non-antibiotic and effective treatment or co-treatment of acne with no side effects, which makes it particularly attractive for cosmetic purposes.     

Therapeutic agents and herbs in topical application for acne treatment

Acne vulgaris suppresses an individual's self-confidence by causing distress with regard to physical appearance, which affects a significant number of individuals during puberty and is delineated by adolescence. Several treatments have been introduced to decrease the aesthetic and psychological problems caused by acne. The topical application of therapeutic agents has been found to be more feasible than hormonal treatment and laser therapy. The ingredients in topical acne treatments, particularly herbs and naturally derived compounds, have received considerable interest as they have fewer adverse effects than synthetic agents.     

清热解毒软胶囊、维胺酯、安体舒通联用治疗面部寻常痤疮的临床疗效观察

目的观察清热解毒软胶囊、维胺酯、安体舒通胶囊联用治疗面部寻常痤疮的临床疗效.方法随机将300例寻常痤疮患者分为2组,治疗组250例,口服清热解毒软胶囊、维胺酯和安体舒通.对照组50例,口服阿奇霉素、维胺酯.2组均以10 d为1个疗程,4个疗程后观察疗效.结果治疗组总有效率96.0%,对照组总有效率74.0%,2组差异有统计学意义(P<0.05).结论清热解毒软胶囊,维胺脂,安体舒通联用治疗面部寻常座疮疗效显著,临床症状改善快.     

In vivo assessment of the efficacy of an innovative face care system in subjects with mild acne vulgaris

The purpose of our studies was to verify efficacy and skin compatibility of a medical face care system containing 2% lactic acid (LA) as active ingredient in a specially designed vehicle (Follicle Targeting System) in adult subjects with mild acne vulgaris. The first study (46 patients) demonstrated superiority of 2% LA in comparison to 2% salicylic acid with respect to number of comedones and inflammatory lesions. The second study evaluated 90 patients receiving distinct combinations of face care products (Eucerin) Impure Skin, Hamburg, Germany), i.e. cleansing gel, facial tonic (2% LA) and cream gel (2% LA). All treatments were performed twice daily over a 12 weeks period. Lesion counts, cyanoacrylate biopsies and determination of quality of life by questionnaires were performed at different timepoints. A reduction of comedones by 56% corresponding to an 46% increase of quality of life index was demonstrated in patients applying cleansing gel, facial tonic and cream gel. For the first time we were able to show a significant improvement concerning the quality of life after using a new face care line. Especially adults with mild forms of acne may benefit from this effective skin care regimen.     

A rapid method to clinically assess the effect of an anti-acne formulation

Historically, clinical evaluation of acne treatment has been based on direct visual assessment and the counting of lesions over a period of several weeks of treatment. However, with advancing technology there has been ever-increasing speed in the effectiveness of these treatments. To successfully assess these faster treatments, acne pathology needs to be evaluated in a shorter time frame. The object of these studies was to develop techniques to evaluate individual acne lesions in a shorter time frame and to assess speedier treatment technologies. Ten healthy volunteers with acne lesions on their upper backs were recruited for the study. Two inflamed acne lesions were selected for each treatment, along with lesions to be left untreated, on each volunteer. Each lesion was marked, photographed, and visually graded. A skin surface microscope (Scopeman) was used to visualize size and to grade the lesions by two experts every day for five days. The sites were treated once a day for the course of the study. There was a remarkable reduction in the size and erythema of acne lesions after treatment with the acne formulation as compared to the untreated and vehicle-treated lesions. Individual lesions, both treated and untreated, appeared resolved in 14 days. This resolution can be noticeably accelerated by topical treatments. We have developed a simple and faster clinical method to evaluate the effects of topical anti-acne technology.     

Bioavailability and storage stability of vitamin A fortificant (retinyl acetate) in fortified cookies

Vitamin A deficiency is one of the major nutritional deficiencies affecting population in developing regions. In Pakistan, 60% of the child deaths are due to diarrhea and respiratory infection, which are associated with vitamin A deficiency. This study was to assess the bioavailability and stability of vitamin A fortificant in cookies fortified with retinyl acetate. Cookies fortified with Vitamin A (retinyl acetate) were manufactured and physically, chemically and sensorial analyzed. Efficacy studies were carried and Serum retinol concentrations were measured to assess the bioavailability of Vitamin A (retinyl acetate), different organ weights were also measured to check the effects of Vitamin A (retinyl acetate) on organ weights and body growth. The treatment T₄ containing (257.85 μg) 45% RDA fortification level of retinyl acetate was judged best considering, physical, chemical and sensory characteristics. Baking losses were lowest in T₄. Efficacy study revealed that Serum retinol concentrations were 125.19 μg/dl in control group and it was raised to 148.64 μg/dl in T₄. Liver, lungs, left kidney, right kidney, heart, spleen, brain, left testicles and right testicles increased in their weights when fed with vitamin A fortified diet as compared to control. Exceptions were only brain and spleen, in spleen it remained stable and brain weight reduced as compared to control. Fortification of cookies with 257.85 μg (45% RDA) of retinol acetate improved nearly all quality attributes and through efficacy studies it was concluded that vitamin A significantly affects growth and body functioning of rats. Concludingly cookies fortified with 257.85 μg of retinol acetate can be used effectively to overcome vitamin A deficiency in the children.     

Improvement of facial skin characteristics using copper oxide containing pillowcases: a double-blind, placebo-controlled, parallel, randomized study

Copper plays a key role in several processes of skin formation and regeneration. Copper has been shown to be absorbed through intact skin. We hypothesized that sleeping on fabrics containing copper-impregnated fibres would have a positive cosmetic effect on the skin. The aim of this study was to confirm our hypothesis. A 4-week, double blind, parallel, randomized study was carried out in which 57 volunteers aged 40–60 years used either copper oxide containing pillowcases (0.4% weight/weight) or control pillowcases not containing copper. Photographs were taken by a professional photographer of each participant at the beginning of the study and at 2 and 4 weeks after the commencement of the study. Two expert graders (a dermatologist and a cosmetologist) evaluated the pictures for the effect on several cosmetic facial skin characteristics. The copper-containing pillowcases had a positive effect for the following facial characteristics: reduction of wrinkles ( P  < 0.001) and crow's feet/fine lines ( P  < 0.001) and improvement of general appearance ( P  < 0.001) at both 2 and 4 weeks. The differences were statistically significant (Wilcoxon scores and chi-squared tests). Consistent sleeping for 4 weeks on copper oxide containing pillowcases caused a significant reduction in the appearance of facial wrinkles and crow's feet/fine lines and significant improvement in the appearance of facial skin. In most trial participants, this effect was already noticeable within 2 weeks of using the copper oxide containing pillowcases.     

The effect of red beet (Beta vulgaris var. rubra) fiber on alimentary hypercholesterolemia and chemically induced colon carcinogenesis in rats

The effect of diet supplemented with 5% and 15% cellulose or with 15% fiber isolated from red beet (Beta vulgaris var. rubra) on the development of alimentary hypercholesterolemia and chemically induced colon carcinoma was studied in male Wistar rats. Hypercholesterolemia was induced by a diet containing 0.3% of cholesterol and colon carcinoma was induced by treatment with dimethylhydrazine (20 mg/kg, 12 doses applied s.c. in one-week intervals). Fibrous matter isolated from red beet contained 89% fiber, of which 9% was in water soluble form. Animals were killed 14 weeks after the application of dimethylhydrazine (i.e. 26 weeks after starting on the diets). Red beet fiber diet (and not the increased cellulose intake) caused a reduction of serum cholesterol and triacylglycerol levels (by 30 and 40%, respectively) and a significant increase in the fraction of cholesterol carried in HDL. This diet induced also a significant decrease (almost by 30%) of cholesterol content in aorta. Higher cellulose content in the diet and even more so the administration of red beet fiber caused a significant reduction of conjugated dienes content in plasma, erythrocytes and in liver. Also observed were increases in the activities of superoxide dismutase and catalase in erythrocytes and in colon and activities of glutathione peroxidase and glutathione-S-transferase in liver. The presence of both higher cellulose content and red beet fiber in the diet significantly reduced the incidence of precancerous lesions--aberrant crypt foci--in the colon. The diet containing red beet fiber did not affect significantly the incidence of colon tumours although the number of animals bearing tumours was reduced by 30%.     

Evaluation of the efficacy of a topical cosmetic slimming product combining tetrahydroxypropyl ethylenediamine, caffeine, carnitine, forskolin and retinol, In vitro, ex vivo and in vivo studies

Three studies were performed to investigate the mechanism of action and evaluate the efficacy of a topical cosmetic slimming product combining tetrahydroxypropyl ethylenediamine, caffeine, carnitine, forskolin and retinol. The Ex vivo study on skin explants showed that caffeine and forskolin both stimulated glycerol release and demonstrates for the first time that retinol and carnitine in combination synergistically stimulated keratinocyte proliferation, which leads to an increase epidermal thickness. The double-blind, randomized, placebo-controlled clinical study associating circumference measurements on five selected parts of the body, cutaneous hydration measurements as well as blinded expert grading of skin aspect was conducted on 78 women who applied the product or placebo twice daily for 12 consecutive weeks. After 4 weeks of twice-daily application of the product, significant reductions in circumference of abdomen, hips-buttocks and waist were already observed. Improvements concerned all the measured body parts after 12 weeks. Orange peel and stubborn cellulite decreased significantly from 4 weeks of treatment and tonicity improved from 8 weeks, demonstrating that the product improved skin aspect. At the end of the study, eight parameters of the thirteen evaluated were significantly improved in the active group and compared with placebo.     

The effect of postharvest calcium application on tissue calcium concentration, quality attributes, incidence of flesh browning and cell wall physicochemical aspects of peach fruits

The effects of postharvest calcium applications on cell wall properties and quality attributes of peach fruits (Prunus persica L. Batsch, cv. ‘Andross’) after harvest or cold storage up to 4 weeks were determined. The fruits were immersed in deionised water or in different calcium sources (calcium chloride, calcium lactate and calcium propionate) at two calcium concentrations (62.5 and 187.5 mM Ca). Calcium concentration profiles in fruits (peel and flesh), in cell wall and in pectin fractions were determined. The calcium content in the peel increased up to 2.7-fold, whereas flesh calcium increased up to 74%, 1 day after immersion. The increase of flesh calcium was accompanied by increase of cell wall calcium, which corresponded to a significant increase of calcium in the water-insoluble pectin fraction. However, calcium became saturated in the water-insoluble, but not water-soluble, pectin fraction with 62.5 mM Ca treatment. Treatment with 62.5 mM Ca salts was as effective as higher concentrations of calcium chloride maintaining tissue firmness during storage. Inversely, calcium lactate and calcium propionate at high concentrations (187.5 mM Ca) caused toxicity symptoms on the fruit surface, expressed as skin discoloration and superficial pitting, leading to additional chemical changes and reduced tissue firmness. Postharvest calcium applications limited the intense of chilling injury symptoms, expressed as flesh browning after 4 weeks cold storage. Peach fruits with severe flesh browning symptoms were characterized by reduced ethylene production, and reduced activities of the pectin modifying enzymes poly-galacturonase and pectin-methyl-esterase.     

Presented at the 16th DGK Symposium, March 2–4, 2005, Leipzig, Germany – Received the Award for the Best Poster Presentation 1Influencing the equilibrium of the cutaneous ecosystem to improve the properties of skin prone to acne

The skin is colonized by a variety of microorganisms such as Propionibacterium acnes, Staphylococcus epidermidis and Malassezia furfur that are in a stable balance and form the resident skin flora. The homeostasis of this ecosystem is of fundamental importance as it plays a barrier role by limiting the invasion and growth of pathogenic bacteria on the skin surface. An internal or external change in the skin environment, a transitory lack of hygiene, a change in hormone status or hyperseborrhea can upset this balance at any time and enable the proliferation of saprophytic skin microorganisms or contamination by pathogens. Hyperseborrhea causes retention lesions such as open comedos and closed microcysts that can be transformed into papulae, pustules or nodules in the case of an inflammatory reaction caused by abnormal bacterial proliferation. These skin disorders are particularly pronounced between the ages of 12 and 25 but nonetheless affect all ages and cause oily skin accompanied by unsightly imperfections that are difficult to camouflage and live with. The skin combats microbial infections with its natural defense system. Keratinocytes produce and secrete a large number of peptides with direct and indirect antimicrobial activity (cathelicidins, β‐defensins). These natural antimicrobial peptides limit the proliferation of pathogenic bacteria and fungi such as Staphylococcus aureus or Candida albicans and can also induce an indirect immune response. They are indispensable for the homeostasis of the cutaneous ecosystem and are over‐expressed by keratinocytes in response to an inflammatory stimulus or an infection. When these natural defenses are disturbed or overwhelmed, they must be stimulated to limit the inflammatory reactions that result in the appearance of skin imperfections such as acne. To this end, we have developed an extract purified from Filipendula ulmaria (meadowsweet) that is rich in phenolic acids. Tested at 1% on human keratinocytes, the F. ulmaria extract stimulated the natural defense functions of the skin by boosting the synthesis of cathelicidins by 130%. In addition, when tested in vivo at 4%, the F. ulmaria extract significantly reduced the lipid index by 12% in 71% of volunteers after 28 days of twice‐daily treatment. The F. ulmaria extract stimulates the natural defense functions of the skin, preventing the proliferation of bacteria on the skin surface and thereby limiting complications from acne: The number of spots and their total occupied surface were significantly reduced by ‐10% and ‐12%, respectively. Finally, dermatological evaluation after 28 days of twice‐daily use showed the capacity of the F. ulmaria extract to significantly improve the quality of skin prone to acne: The homogeneity of skin grain was improved (+21%), the number of inflammatory lesions reduced (‐20%) and the infiltration of lesions decreased (‐22%).     

Change of Hygienic Quality and Freshness in Tuna Treated with Electrolyzed Water and Carbon Monoxide Gas during Refrigerated and Frozen Storage

ABSTRACT:  Among different fish slices used for sashimi preparation, tuna is the most popular and preferable fish type for Taiwanese people. To improve the hygienic quality of fish slices, electrolyzed (EO) water containing 10, 50, and 100 mg/L chlorine, was used in combination with CO gas treatment. Effect of different treatment on aerobic plate count (APC), volatile basic nitrogen (VBN), K value, and Hunter L*, a*, b* values of yellow-fin tuna steak during storage (4 °C and −20 °C) were evaluated. It was found that APC, VBN, and K values increased with storage time for all treatment. Except for K value, APC and VBN of tuna steak treated with the combination of more than 50 mg/L chlorine EO water and CO gas had the lowest value after 8 d of refrigerated storage. Hunter a* value of tuna steak treated with only CO gas was the highest, followed by those treated with EO water and CO gas. These results demonstrated that EO water containing 50 mg/L chlorine combined with CO gas treatment in tuna fish steak would be an effective method for enhancing the hygienic quality and freshness for tuna meat and extending refrigerated storage time. Tuna treated with EO water containing 100 mg/L chlorine and CO gas combination had the lowest APC immediately after treatment and reduced further to below detection limit after 1 mo frozen storage at −20 °C.     

Biochemical composition and storage stability of a yogurt-like product from African yam bean (Sphenostylis stenocarpa)

The biochemical and storage properties of African yam bean ( Sphenostylis stenocarpa ) yoghurt-like product were evaluated. Milk extracted from the bean flour using hot water was supplemented with 4% milk protein concentrate (MPC), 0.15% dairy calcium (DC) and 0.5% gelatine (G) (singly or in combination). The milk was fermented with Streptococcus thermophilus and Lactobacillus delbrueckii spp bulgaricus at 43 °C for 3–5 h. Supplemented African yam bean (AYB) yoghurts had a gel-like consistency unlike the control (unsupplemented) sample. Total solids, protein, fat, ash, lactic acid bacterial count, lightness (L-value) and viscosity were improved by supplementation. Riboflavin and antioxidants were reduced; macroelements and thiamine were increased by 0.71–15.6% and 16.7%, respectively, because of fermentation. The stability of the product during storage at 4 °C was improved by supplementation and stirring. The pH of the supplemented product ranged from 4.45 to 4.54 and microbial counts from 2.6 × 10⁶ to 1.6 × 10⁸ during storage for not more than 3 weeks.     

Effectiveness of immersion treatments with acids, trisodium phosphate, and herb decoctions in reducing populations of Yarrowia lipolytica and naturally occurring aerobic microorganisms on raw chicken

Yarrowia lipolytica, one of the predominant yeasts in raw poultry, is believed to play a role in spoilage. This study was undertaken to investigate treatments to control the growth of Y. lipolytica on raw chicken stored at refrigeration temperature. Raw chicken wings inoculated with a mixture of five strains of Y. lipolytica isolated from raw poultry were dipped in solutions containing 2, 5, or 8% lactic acid, 2% lactic acid containing 0.2, 0.4, or 0.8% potassium sorbate or sodium benzoate, and 4, 8, or 12% trisodium phosphate solution. Populations of the yeast and total aerobic microorganisms were determined before and after treatment. Immersion of wings in 2% lactic acid (with or without 0.2% potassium sorbate or sodium benzoate) or 4% trisodium phosphate caused a significant (alpha = 0.05) reduction in numbers of Y. lipolytica and aerobic microorganisms. Treatment with 2% lactic acid containing 0.4 or 0.8% preservative did not result in additional significant reductions. Treatment of chicken wings with 2% lactic acid or 8% trisodium phosphate significantly reduced numbers of Y. lipolytica by 1.47 and 0.65 log10 cfu/g, respectively, and aerobic microorganisms by 2.60 and 1.21 log10 cfu/g, respectively, compared to controls. Growth of Y. lipolytica on wings stored at 5 degrees C for up to 9 days, however, was not affected by these treatments. Significant reductions in the population of Y. lipolytica occurred when the yeast was inoculated into 100% basil, marjoram, sage, and thyme decoctions, but not in 100% oregano or rosemary decoctions, held at 5 degrees C for 24 h. Treatment of chicken wings with 100% sage or thyme decoctions significantly reduced populations of Y. lipolytica but did not control its growth during storage at 5 degrees C for up to 9 days. The small, temporary decreases in numbers of Y. lipolytica and aerobic microorganisms resulting from immersion treatment of chicken wings with sage and thyme decoctions render these treatments of questionable value as preservation interventions.     

Controlling Listeria monocytogenes on sliced ham and turkey products using benzoate, propionate, and sorbate

The objective of this study was to identify concentrations of sorbate, benzoate, and propionate that prevent the growth of Listeria monocytogenes on sliced, cooked, uncured turkey breast and cured ham. Sixteen test formulations plus a control formulation for each product type were manufactured to include potassium sorbate, sodium benzoate, or sodium propionate, used alone and combined (up to 0.3% [wt/wt]), or with sodium lactate-sodium diacetate combinations. Products were inoculated with L. monocytogenes (5 log CFU/100-g package) and stored at 4, 7, or 10 degrees C for up to 12 weeks, and triplicate samples per treatment were assayed biweekly by plating on modified Oxford agar. Data showed that 0.1% benzoate, 0.2% propionate, 0.3% sorbate, or a combination of 1.6% lactate with 0.1% diacetate prevented the growth of L. monocytogenes on ham stored at 4 degrees C for 12 weeks, compared with greater than a 1-log increase at 4 weeks for the control ham without antimicrobials. When no nitrite was included in the formulation, 0.2% propionate used alone, a combination of 0.1% propionate with 0.1% sorbate, or a combination of 3.2% lactate with 0.2% diacetate was required to prevent listerial growth on the product stored at 4 degrees C for 12 weeks. Inhibition was less pronounced when formulations were stored at abuse temperatures. When stored at 7 degrees C, select treatments delayed listerial growth for 4 weeks but supported significant growth at 8 weeks. All treatments supported more than a 1-log increase in listerial populations when stored at 10 degrees C for 4 weeks. These results verify that antimycotic agents inhibit the growth of L. monocytogenes on ready-to-eat meats but aremore effective when used in combination with nitrite.     

Microbiological, Sensory and Chemical Characteristics of Vacuum-Packaged Cooked Beef Top Rounds Treated with Sodium Lactate and Sodium Propionate

Cooked, vacuum-packaged beef top rounds containing 3% sodium lactate (NaL) or 3 or 4% NaL in combination with 0.1 or 0.2% sodium propionate (NaP) were stored for up to 84 days at 4°C. Addition of any of the treatments greatly reduced total Aerobic Plate Counts (APC). Positive flavor notes associated with fresh beef were enhanced by ingredient addition and tended to be highest in roasts with 3% NaL + 0.2% NaP. Cooked roast beef color was enhanced by addition of NaL alone or in combination with 0.1% NaP. Lipid oxidation and water activity were decreased by addition of NaL with NaP and pH and cooked yield were increased with any level or combination of ingredients.     

Biological control of blue mould on apple by a strain of Candida sake under several controlled atmosphere conditions

The biocontrol potential of the yeast Candida sake (CPA-1) against Penicillium expansum decay of apples under several controlled atmosphere conditions was investigated. In a laboratory trial under different commercial cold storage conditions, increasing concentrations of C. sake improved decay control. A maximum reduction of decay was achieved at 3% O2-3% CO2 atmosphere. It amounted to a 97% lesion reduction after treatment with a suspension containing 2.4 x 10(6) CFU/ml of C. sake (CPA-1). In a semi-commercial trial at 1 degree C with wounded fruits, the reduction in decay diameter caused by C. sake exceeded 80% after 60 days at 21% O2 and 60% after 120 days of storage under controlled atmosphere conditions. For seven controlled atmosphere conditions studied, a significant influence by C. sake on the P. expansum decay was observed, and the lesion size was reduced more than 70% by C. sake at 10(7) CFU/ml. The populations of C. sake (CPA-1) on the apple surface followed the same pattern under all controlled atmosphere conditions studied. They decreased 4-10-fold during the first 2 weeks, followed by an increase to the initial level after 45 days, and thereafter the count remained constant for the period of 90 days examined. This indicated the capacity of C. sake (CPA-1) to colonize the surface of apples under various storage conditions. The ability to colonize was even higher in apple wounds.     

Storage technology of onion bulbs c.v. Rouge Amposta: effects of irradiation, maleic hydrazide and carbamate isopropyl, N-phenyl (CIP) on respiration rate and carbohydrates

The effects of γ-irradiation, maleic hydrazide (MH) and carbamate isopropyl, N-phenyl (CIP) on the carbohydrate content, respiration rate (RR) sprouting and rotting of red onion bulbs ( Allium cepa L.) c.v. Rouge Amposta stored at 4, 10 and 20 °C were investigated. Between 6 and 8 weeks soluble sugars increased in concentration and varied between 6.0 and 6.5% fresh weight both at 10 and 20 °C. However, this peak did not exceed 6.0% fresh weight at 4 °C. The basal amount of soluble sugars was about 3% fresh weight. The content appeared to be influenced by temperature, with greater accumulation at 10 and 20 °C than at 4 °C. The RR increased when the bulbs sprouted, whereas it was reduced by the following treatments: irradiation, MH and CIP, the respiration of irradiated bulbs decreased during the final stage of storage because of the death of the sprouts. The chemical treatment used were effective in controlling sprouting of the bulbs during storage, although not as effective as irradiation and chilling.     

Surface application of lysozyme, nisin, and EDTA to inhibit spoilage and pathogenic bacteria on ham and bologna

A study was conducted to determine if the effectiveness of an antimicrobial treatment for cooked ham and bologna would be increased or maintained when applied in a surface coating. Cooked 10-g disks of ham and bologna sausage received one of three treatments: no coating (control), coating with 0.2 g of 7% (wt/vol) gelatin gel (gel-control), or coating with 0.2 g of 7% gelatin gel containing 25.5 g/liter of lysozyme-nisin (1:3) plus 25.5 g/liter of EDTA (gel-treated). The samples were then inoculated with one of six test organisms: Brochothrix thermosphacta, Escherichia coli O157:H7, Lactobacillus sakei, Leuconostoc mesenteroides, Listeria monocytogenes, or Salmonella Typhimurium. Inoculated samples were vacuum packed and stored at 8 degrees C for 4 weeks. The antimicrobial gel treatment had an immediate bactericidal effect up to 4 log CFU/cm2 on the four gram-positive organisms tested (B. thermosphacta, Lactobacillus sakei, Leuconostoc mesenteroides, and Listeria monocytogenes) and inhibited the growth of these organisms during the 4 weeks of storage. The antimicrobial gel treatment also had a bactericidal effect on the growth of Salmonella Typhimurium during storage. The numbers of E. coli O157:H7 on ham were reduced by 2 log CFU/cm2 following treatment with both antimicrobial-containing and non-antimicrobial-containing gels during the 4-week storage period. No effect was observed on the growth of E. coli O157:H7 on bologna.     

High hydrostatic pressure inactivation of Lactobacillus viridescens and its effects on ultrastructure of cells

The effect of high hydrostatic pressure treatment on Lactobacillus viridescens, a major spoilage micro-organism of processed meat, was investigated. When pressure was applied at 400, 500 and 600 MPa for 5 min, cell survival in MRS broth was reduced approximately by 2, 7 and 8 log cycles, respectively. The combination of high pressure and temperature increase showed synergistic effects on microbial inactivation. Empty cavities in the cell and DNA denaturation were observed after pressure treatment above 400 MPa. The level of microbial inactivation when Lb. viridescens was pressured in protein-fortified MRS broth and ham were less than half compared with the inactivation achieved in peptone water. Increasing the temperature during high-pressure treatment solved these adverse effects in the ham.