Microbiological quality of fruit juices sold in Tripoli–Libya

Fruit juices are becoming an important part of the modern diet in many communities. Data regarding the microbiological quality of foods, particularly fruit juices, sold in Libya and the neighboring North African countries are few if not lacking. Using standard microbiological procedures, 146 fruit juice samples sold in Tripoli were examined. Total bacterial counts (TBC) of samples examined ranged between <1 and 3 × 10⁵ CFU/ml (mean = 5 × 10⁴). Almond juice showed the highest TBC ranging between 1.8 × 10³ and 3 × 10⁵ (mean = 1.7 × 10⁵). Staphylococcus aureus was detected in 8 (5.5%) samples, Streptococcus spp. in 4 (2.7%), coliforms in 33 (22.6%), Escherichia coli (none were of serogroup O157) in 3 (2.1%), Klebsiella pneumonia in 17 (11.6%), Aeromonas spp. in 3 (2.1%), Pseudomonas aeruginosa in 6 (4.1%), Candida albicans in 18 (12.3%), Candida spp. in 109 (74.7%) and other yeasts in 85 (58.2%). Many of these organisms can cause disease in humans, which indicates that a large number of juices tested did not fulfill the Libyan guidelines for the microbiological quality of juices. Application of the HACCP system should be introduced into the food industry sector to improve the quality of fruit juices and other foods manufactured in Libya.     

The in vitro antimicrobial and antioxidant activities of the essential oils and methanol extracts of endemic Thymus spathulifolius

The present study was conducted to evaluate the in vitro antimicrobial and antioxidant properties of essential oil and methanol extracts from a unique and endemic plant, Thymus spathulifolius (Hausskn. and Velen.). The antimicrobial test results showed that the essential oil of T. spathulifolius strongly inhibited the growth of test microorganisms studied, except for 4 fungi species while polar and non-polar subfractions of the methanol extract had moderate antibacterial, but not antifungal and anticandidal activity. The antioxidative potential of the samples was evaluated using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene–linoleic acid systems. The polar subfraction of the methanol extract was able to reduce the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) with an IC₅₀ of 16.15 ± 0.5 μg/ml, which was lower than that of synthetic antioxidant, BHT, (19.8 ± 0.5 μg/ml). Inhibition values of linoleic acid oxidation were calculated as 92% and 89% for the oil and the polar subfraction, respectively. Gallic acid equivalent total phenolic constituent of the polar subfraction was 141.00 ± 0.90 μg/mg (14.1%, w/w). The chemical composition of a hydrodistilled essential oil of T. spathulifolius was analyzed by a GC and GC/MS system. A total of 28 constituents representing 99.2% of the oil were identified; thymol (36.5%), carvacrol (29.8%), p-cymene (10.0%) and γ-terpinene (6.3%) were the main components comprising 82.6% of the oil. Results presented here may suggest that the essential oil and extracts of T. spathulifolius possess antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient in food and/or pharmaceutical industry.     

Implementation of HACCP in food businesses: the way ahead

Food-borne diseases constitute an important public health problem in both developed and developing countries. Although their health and economic aspects are often obscured by insufficiency of data, available evidence on incidence and associated costs of medical care indicates that they are a major cause of morbidity, and a drain on resources. A joint WHO/FAO expert committee on food safety asserts that illness due to contaminated food is probably the most widespread health problem in the contemporary world, and an important cause of reduced economic productivity. Given the inadequacies of traditional approaches to food safety control, viz. inspection and end-product testing, there is a need to apply such other strategy of proven effectiveness as the Hazard Analysis Critical Control Points (HACCP) system which has been described as the most viable means for the prevention of food-borne diseases yet devised. While there is an extensive literature suggesting the effectiveness of HACCP in preventing food-borne diseases, food operators have yet to embrace it with the anticipated enthusiasm. This paper examines factors that are likely to hinder wider acceptance and practical implementation of HACCP in food operations and discusses measures to overcome them. It is concluded that HACCP training and education of food operators and food regulatory officials is a conditio sine qua non for the realization of the fullest benefits of the strategy.     

Molecular grouping and pathogenic analysis of Listeria monocytogenes of clinical and food origin

The phylogenesis and pathogenesis of ten Chinese Listeria monocytogenes isolates of clinical (n = 2) and food (n = 8) origin have been investigated in this study. The 597 bp nucleotide sequence at 3′ terminal of actA gene of these L. monocytogenes isolates were amplified and sequenced. Compared with those of published sequences of the corresponding region within the same gene, the phylogenetic tree was constructed using MEGA2.1 software. It was shown that one clinical strain 1579 and food strains YZ5, YZ7, YZ8 belong to lineage I, while the other clinical strain 1191, and food strains YZ1, YZ2, YZ3, YZ4, YZ6 belong to lineage II. The virulence of these strains based on experimental infection model of SPF chick embryos were determined, and compared between L. monocytogenes isolates of two lineages and their hemolytic activity was assessed according to the development of zones of hemolysis around the colonies. Isolates of lineage I showed high virulence while isolates of lineage II (except clinical isolates 1191) exhibited low virulence, since 100% mortality rate and relative short time to death for embryos were observed for strains of lineage I, while 20–30% mortality rate and long time to death for embryos were observed for isolates of lineage II. Hyper-virulent isolate 1579, YZ8 and lower-virulent isolates YZ2, YZ3, YZ4 and YZ6 show strong hemolytic activity while hyper-virulent isolate 1191, YZ5, YZ7 and lower-virulent isolate YZ1 show weak hemolytic activity. The discrepancy between virulence and hemolytic activity indicates that L. monocytogenes hemolytic activity is not directly proportional to their virulence and thus it can not be used as a reliable criteria for assessment of the virulence of L. monocytogenes.     

Reducing nitrite content in hot dogs by hurdle technology

The objective of the present study was to reduce nitrite content in hot dogs using hurdle technology without sacrificing product safety and quality. In the present study, the water activity of the hot dog was adjusted to 0.95 by the addition of humectants. Although the pH at the hot dog was adjusted with Glocono-delta-lacton to 5.4, the product had (p > 0.05) the least acceptance on account of the organoleptic changes (sour taste). Moreover, the temperature of 80 ± 1 °C for an hour with the aim of achieving an internal temperature of 75 °C was applied. Subsequently, the temperature of the hot dog samples reduced to around 5–6 °C within 40–45 min, and afterwards the sausages were kept at chilled temperature (>3 °C but 10 °C) throughout their shelf life. There was a decrease in total aerobic counts in hurdle treated hot dogs (with 50 ppm nitrite), compared to the control (with 120 ppm nitrite), whereas Clostridium perfringens counts and Clostridium botulinum detection were the same (p < 0.05) in both hurdle treated and control samples. The obtained results of present study clearly showed that both hurdle treated sample and control had the same (p < 0.05) overall acceptability and sensory attributes.     

Inhibition of food poisoning and pathogenic bacteria by Lactobacillus plantarum strain 2.9 isolated from ben saalga, both in a culture medium and in food

The bacteriocinogenic strain Lactobacillus plantarum 2.9 isolated from the traditional pearl millet-based African fermented food ben saalga was tested for inhibition of food poisoning and pathogenic bacteria in MRS broth and in a malted millet flour slurry. In MRS broth, strain 2.9 completely eliminated Bacillus cereus, Escherichia coli O157:H7 and Salmonella enterica cells within 48 h incubation at 22–30 °C. A much lower inhibition was observed at 15 °C. The inhibitory effect of strain 2.9 on the above-mentioned target bacteria was corroborated in the malted millet flour slurry, reducing viable cell counts below detection levels after 8 h storage for B. cereus or after 24 h for S. enterica and 48 h for E. coli. An Enterobacter aerogenes strain was only moderately inhibited in the slurry. Results from the present study suggest that strain 2.9 could be used as starter culture to improve the microbiological safety of fermented ben saalga.     

Microbiological profile of helva sold at retail markets in Izmir city and the survival of Staphylococcus aureus in this product

The objective of this research was to determine the microbiological profile of tahin helva, a low moisture confectionery. A total of 63 tahin helva samples were collected from the retail markets in Izmir, Turkey. These samples were examined by standard procedures for aerobic plate count (APC) and counts of moulds and yeasts, Enterobacteriaceae, Staphylococcus aureus and Salmonella spp. APC of samples ranged from <10 to 1.6 × 10⁵ cfu/g. The counts for moulds, yeasts and Enterobacteriaceae ranged from <10 to 1.8 × 10³, <10 to 7 × 10², <10 to 8.5 × 10² cfu/g, respectively. None of the samples contained S. aureus or Salmonella. The potential for survival of S. aureus in the product stored at refrigeration (4 °C) and room (20 °C) temperatures was evaluated by artificial contamination. S. aureus cells were still recovered after 9 months of storage at both temperatures. The results of this investigation indicate that S. aureus contamination of tahin helva, (a_w of 0.172) may constitute a potential public health hazard, depending on the extent of contamination and mishandled exercise at the sale area and the kitchen.     

Characteristics of Bacillus cereus isolates from legume-based Indian fermented foods

An antibiogram of 48 strains of Bacillus cereus isolated from 6 different kinds of legume-based Indian fermented foods (amriti, dhokla, dosa, idli, papad and wadi) was generated against 18 different antibiotics that are commonly used against foodborne diseases, mainly gastroenteritis. Each of the isolates was found to be resistant against at least nine different antibiotics. Production of extracellular enzymes, namely protease, lipase and amylase by 33%, 27% and 46%, respectively, of the isolates indicates their potentiality for food spoilage. In brain–heart infusion broth supplemented with glucose, the D_100 °C-values for the tested 12 strains ranged from 3.0 to 9.2 min. In nutrient broth, the minimum and maximum pHs permitting growth of B. cereus were 5.3 and 11.6, respectively. The minimum inhibitory concentrations of sodium chloride, benzoic acid and sorbic acid for the growth of the isolates were 65–85 mg ml⁻¹, 400–700 μg ml⁻¹ (pH 5.0–4.2) and 500–600 μg ml⁻¹ (pH 5.0–4.8), respectively. Of the tested 10 strains, eight were resistant to 300 μg nisin ml⁻¹ (pH 5.0). While studying the combined effect of selected hurdles on the growth of an isolate, the judicious combination considered was 20 mg sodium chloride, 300 μg benzoic acid and 25 μg nisin ml⁻¹ at pH 5.6. The whole-cell protein fingerprinting (WCPF) analysis using SDS–PAGE revealed a high level of diversity among the isolates. At 60% similarity level, the WCPF profiles could be grouped into four major clusters which were divided into 34 subclusters. Most of the subclusters were source-wise homogeneous.     

Survival and growth of Listeria monocytogenes on sausage formulated with inoculated and stored rework product

To assess the effect of including contaminated rework on survival and growth of Listeria monocytogenes, two sausage formulations (one American, Bologna sausage; and one Bulgarian, Stranja sausage) were inoculated with the pathogen and stored for 4 days at 10 °C plus 15 h at 30 °C. After storage, both rework types were included (at 20% and 40%) in corresponding fresh sausage emulsions and heated to 68, 70 and 71.7 °C; fresh Bologna and Stranja emulsions served as controls and were inoculated with 24 h broth cultures of the same 10-strain mixture of L. monocytogenes and thermally treated to the same temperatures. The results showed that heating to 68 and 70 °C inactivated 3–4 log CFU/g of the initial concentration of L. monocytogenes cells (>7 log CFU/g), while heat treatment to 71.7 °C in the center of experimental samples reduced counts by 6 log CFU/g. Survival of L. monocytogenes in samples heated to 68 and 70 °C was higher in controls. Control samples of Stranja emulsion heated to 71.7 °C allowed higher growth (P < 0.05) during storage (5 days at 10 °C) as compared to other control and experimental rework samples. The Stranja emulsion had a higher fat content (20.2%) compared to the Bologna emulsion (11%). This study provides evidence about the possible danger when potentially contaminated rework is stored and then introduced into fresh product formulations.     

Implementation of HACCP and prerequisite programs in food businesses in Turkey

The objectives of this study was to determine food safety practices and procedures related to the hazard analysis critical control point (HACCP) programme and prerequisite programme implementation in food businesses. One hundred and nine food businesses in Turkey were assessed for HACCP-prerequisite programmes and food safety practices. Only eight food businesses had implemented the HACCP system in food businesses. Directors and employees often have insufficient knowledge regarding the basics of food hygiene. Results indicated that proper food safety practices and prerequisite food safety programmes for HACCP were often not being followed in many food businesses. Time and temperature errors and inadequate handwashing practices were wide in the most food businesses. Emphasis on implementing prerequisite programmes in preparation for HACCP is needed in food businesses. The problems of implementing HACCP in food businesses have been namely a low level of food hygiene management training, high staff turnover rate, lack of motivation, lack of financial resources, inadequate equipment and physical conditions of the facility and failure of government.     

Effect of nisin on the storage of sous vide processed Korean seasoned beef

Seasoned beef called Jangzorim in Korea is produced by boiling in soy sauce, and is a popular food in Korea. The aim of this study is to evaluate the microbial safety and physical qualities of sous vide processed seasoned beef, and the effect of nisin during storage. Sous vide processed packages with or without nisin (100 IU or 500 IU) were stored at 4 °C or 25 °C for 60 days, and samples measured for quality at regular intervals throughout this storage period. In the case of 25 °C storage, the number of mesophilic microorganisms in seasoned beef packages without nisin increased markedly, but with nisin there was no observed increase. Psychrotrophic microorganisms, anaerobic microorganisms, and B. cereus cells showed similar trends, although C. perfringens was not detected in all samples. At 25 °C storage, changes in the cutting force of packages containing nisin showed no significant change, packages without nisin decreased markedly. The colour of packages without nisin showed a drastic decrease in lightness (‘L’) while no changes were observed in packages with nisin.     

Occurrence of contaminants in foods commonly consumed in Bahrain

The occurrence of mycotoxins (aflatoxins, zearalenone, deoxynivalenol), heavy metals and pesticide residues in 198 susceptible food commodities available in Bahrain was determined. Aflatoxins were found in many of the foods tested and three samples of red chili powder (35.9, 52.6 and 69.2 ng/g), one sample of black pepper powder (27.7 ng/g) and one sample of unshelled pistachio nuts (81.6 ng/g) exceeded the maximum allowable limit of aflatoxins. Zearalenone was present in some samples including cornflakes (3.1 ng/g) and crushed wheat (0.3 ng/g). Although many samples contained heavy metals, one sample of cinnamon powder (13.0 μg/g) and one sample of black pepper powder (11.2 μg/g) exceeded the maximum allowable limit for lead. The average levels of cadmium were highest in cinnamon powder (0.3 μg/g) and ginger powder (0.3 μg/g). Some amount of pesticides was found in cumin powder (0.06 μg/g of lindane), turmeric power (0.04 μg/g heptachlor) and coriander powder (0.4 μg/g permethrin). Almonds, peanuts, cashew nuts infant formulas were free of contaminants. Although the contamination of most foods in Bahrain was within the limit, strengthening of the food control systems is important.     

Determination of biogenic amines in sucuk

The biogenic amines content of sucuk (Turkish dry fermented sausage) were determined on 30 samples obtained from retail markets and butchers in Turkey. Also, pH and a_w values, microbiological properties, and NPN levels of these samples were analyzed. The most important biogenic amines were tyramine (range 2.4–676 mg/kg), followed by putrescine varied from not detected to 364 mg/kg. Histamine content was under 50 mg/kg in 80% of the samples while it was over 100 mg/kg in only one sample. Tryptamine was detected in 16 of 30 samples in the range of 1.2–82.3 mg/kg.

Lactic acid bacteria, Micrococcus/Staphylococcus and Enterobacteriaceae counts of samples varied from 2.84 to 8.85 log cfu/g, <2.00 to 6.74 log cfu/g, and <2.00 to 5.04 log cfu/g, respectively. pH values were varied between 4.53 and 6.29 while water activity (a_w) were measured to be between 0.761 and 0.960. NPN values were determined to be between 1.47% and 4.10%. Generally, total amine content was high in samples that had high NPN levels.     

HACCP effectiveness between ISO 22000 certified and non-certified dairy companies

The purpose of the study is to determine the differences between the ISO 22000 certified and non-certified dairy companies with regard to the HACCP (Hazard Analysis Critical Control Points) Food Safety System (FSS) effectiveness. The HACCP FSS effectiveness is defined in the present study as the degree of the achievement of the system objectives (identification, assessment and the control of food borne safety hazards). A research study was carried out in 74 Greek dairy companies using a structured questionnaire. The differences between the ISO 22000 certified and non-certified dairy companies (both implementing HACCP principles) with regard to HACCP effectiveness are determined through non parametric tests such as the Chi-square Test and the Mann–Whitney Test. The vast majority of the participating in the present study dairy companies are small and medium-sized enterprises (SMEs). The ISO 22000 certified dairy companies significantly outperform the non-certified with regard to the HACCP FSS effectiveness, in other words to the degree to which the objectives of HACCP are achieved. Thus, managers of dairy SMEs taking advantage of the structured organization and the documented procedures provided by the ISO 22000 standard can increase the level of achieving the objectives of the HACCP FSS, in other words HACCP effectiveness. In doing so, dairy SMEs can set the foundations in order to optimize the conditions under which safe food is provided, minimize the possibility of food non-conformities and scandals, increase market share and consequently withstand the current downturn.     

Barriers of HACCP team members to guideline adherence

A cognitive-behavior model to evaluate barriers to HACCP guideline adherence by HACCP team members was developed. It was based on the theory of experiential learning where knowledge, attitude and behavior must be sequentially overcome. Twenty-seven HACCP team members from four food processors participated to assess barriers to guideline adherence. Non-awareness to HACCP guideline was a major barrier. The national government was recognized as key source of HACCP information. Commitment to adopt HACCP guideline was established. Also, the need for food processor management to understand that teams must be multidisciplinary to ensure guideline adherence has been established.     

The effect of applying GMP and HACCP to traditional food processing at a semi-commercial kenkey production plant in Ghana

To manage the hazards, aflatoxins and enteric pathogens, associated with the production of an indigenous African fermented maize product, kenkey, HACCP was implemented at a semi-commercial kenkey production plant in Accra. As a prerequisite programme, the facility was upgraded and GMP implemented before HACCP. The effectiveness of GMP and HACCP was assessed by monitoring the environment and kenkey production, as well as the auditing and verification of HACCP. Air sampling and swapping of equipment surfaces revealed a microbiota which was consistent with the fermented product. Monitoring showed that the raw materials, products, processing parameters, etc, conformed to the critical limits within which the safety of the food product would be ensured. This was confirmed by the results of laboratory analysis of raw materials, intermediary and final products. Escherichia coli, Staphylococcus aureus, Enterococcus, Salmonella, Bacillus cereus, and Vibro cholera were not detected in any of the finished products and the level of total aflatoxins in the kenkey samples were between 17.2 and 14.5 μg/kg. Levels of aflatoxins in kenkey samples reported at the plant before implementation of GMP and HACCP were between 64.1 and 196 μg/kg. Application of GMP and HACCP was therefore found to be effective as a quality management system for assuring the safety of kenkey in the traditional processing of maize into kenkey.     

Prevalence of Listeria monocytogenes in delicatessen food products in China

This study was to investigate the prevalence of Listeria monocytogenes in delicatessen food, raw materials and environmental samples in food processing chain. Two hundred and forty-five samples of delicatessen foods in markets, 98 samples of cooked foods from restaurants and hotels, 154 samples of food product contact surfaces such as counters, iceboxes and chopping blocks etc. from processing and selling sites, 51 environmental samples from the food-cooking rooms of restaurants and hotels were collected and detected for the prevalence of L. monocytogenes. The results showed that there were 32 strains isolated from delicatessen foods in the market and the average prevalence was 13.06% which is significantly higher (p < 0.01) than those isolated from cooked foods in hotels and restaurants (1.02%) suggesting that the delicatessen food products may be contaminated during the delivery from hotels and restaurants to the markets. Ten strains were isolated from 335 raw materials and 21 strains were isolated from 154 processing equipments in selling and processing sites. No strains were isolated from 51 samples of equipments in cooked food rooms of hotels and restaurants. The study shows that the prevalence of L. monocytogenes in delicatessen foods in the market was significantly higher than those in the cooked foods of hotels and restaurants, and therefore, the critical control points were: (1) to establish relative closed selling rooms; (2) to establish the sterilizing measures to keep the delicatessens from being contaminated with L. monocytogenes during the delivery from restaurants or hotels to the retail markets.     

Assessment of estimated daily intake of nitrite by average consumption of processed foods in Korea

This study has been performed to estimate the average daily intake of nitrite used in Korea as a color fixative. The crude estimation of daily intake was calculated based on maximum permitted levels (MPL) and national food disappearance data in 1998. In order to refine estimated daily intake (EDI), daily food consumption nationwide National Health and Nutrition Survey in 1998 and the concentration of nitrite in their permitted foods were applied. The crude EDI of nitrite was 17.85 μg/kg bw/day, representing 25.5% of acceptable daily intake (ADI) assigned by JECFA. The refined average EDI for nitrite was 0.87 μg/kg bw/day, representing 1.25% of ADI. For average consumers of age–sex groups ranged from 0.2 to 4.8 μg/kg bw/day, representing 0.3%–6.9% of the ADI.     

Analysis of 140 pesticides from conventional farming foodstuff samples after extraction with the modified QuECheRS method

Pesticides in foodstuff are becoming a major issue due to their intensive use in agriculture. Thus an appropriate control of their residues in food samples has to be operated. In this study we analysed 105 pesticides with GC/SQ-MS and 46 pesticides with HPLC/IT-MS after extraction with the QuECheRS method in four matrices (grape, lemon, onion and tomatoes). For GC-amenable substances, the LOD and LOQ ranged from 0.4 to 48.2 μg/kg and from 1.2 to161 μg/kg, respectively. For HPLC-amenable substances, they varied from 1.0 to 115 μg/kg and from 3.3 to 382 μg/kg, respectively. With GC/MS, 61–82% of the substances showed a recovery in the range of 70–110% and 6–30 % presented a recovery higher than 110% at the 500 μg/kg fortification level. With HPLC/MS, 87–93% of the substances presented recoveries in the range of 70–110% at the 500 μg/kg fortification level compared to 78–85% at the 50 μg/kg fortification level. Lemon and onion showed poor recoveries but are known to be difficult matrices (high acidic and high sulfur content, respectively). The method was proved to be repeatable with RSD lower than 20% at 500 μg/kg and lower than 15% at 50 μg/kg with both devices.     

Critical factors,food quality management and organizational performance

This paper proposes a model for measuring the effectiveness of quality (ISO 9001) and food safety (HACCP) systems, based on their stated objectives, when these systems are jointly implemented in a food company. In addition, it investigates the critical factors for effective implementation (CFEI) of the ISO 9001 and HACCP systems; and examines the degree to which the combined implementation of ISO 9001 and HACCP influences the overall performance of the certified firms. To achieve these objectives, primary field data was collected through an empirical survey that was conducted among 347 food companies in Greece, which were certified to ISO 9001, HACCP and/or ISO 22000 systems. Initially, Exploratory Factor Analysis (EFA) and then Confirmatory Factor Analysis (CFA) were applied. The connections among the non observed model factors were verified through Structural Equation Modeling (SEM) inspection. The findings suggest that “employee attributes”, “organizations' attributes” and “internal business motives” make a significant contribution to the effective implementation of the ISO 9001 and HACCP systems. In addition, the effective implementation of the ISO 9001 and HACCP systems contribute to the business performance of companies in the Greek food industry. The evidence provided in this study helps managers to realize the importance of CFEI and the effective combined implementation of these systems in order to provide the necessary resources and support and develop the necessary policies, practices and procedures.