Salad Ingredients Research Articles

Modelling of transpiration rate of grape tomatoes. Semi-empirical and analytical approach

Transpiration is a well known physiological process of water loss from fresh products, associated with visual and texture degradation and loss of market value. A loss of 3–5% of the initial mass may cause in fresh products loss of freshness and visual attractiveness. Grape tomato has been increasingly accepted by consumers as “snacking tomato” and as an ingredient in mixed salads of fresh-cut vegetables. An experimental procedure was developed to record the associated with transpiration, water loss in grape tomatoes (Solanum lycopersicum, Lobello F1), at temperatures 10, 15 and 20 °C and relative humidity 70, 80 and 92%. Water activity was calculated and correlated with the respective mass loss; its average value was found 0.988 ± 0.01. The mean transpiration rates ranged between 0.012 and 0.058 mg cm−2 h−1 for water vapour pressure deficit range of 0.061–0.662 kPa. A semi-empirical and an analytical model were developed to correlate the mass loss of grape tomatoes with the storage conditions (temperature and relative humidity) and storage time. Both provided satisfactory fit to the experimental data. Finally, the air-film mass transfer coefficient (ka) and skin mass transfer coefficient (ks) were calculated and the ks coefficient correlated efficiently with an exponential equation with the respective water vapour pressure deficit.

A foodborne outbreak of Aeromonas hydrophila in a college, Xingyi City, Guizhou, China, 2012

On 12 May 2012, over 200 college students with acute diarrhoea were reported to the Guizhou Center for Disease Control and Prevention. We conducted an investigation to identify the agent and mode of transmission and to recommend control measures. A suspected case was a person at the college with onset of ≥two of the following symptoms: diarrhoea (more than three loose stools in 24 hours), abdominal pain, vomiting or fever (>37.5C) between 6 and 15 May 2012. A confirmed case also had a positive Aeromonas hydrophila culture from a stool sample. A retrospective-cohort study of 902 students compared attack rates (AR) by dining place, meals and food history. We reviewed the implicated premise, its processes and preparation of implicated food. We identified 349 suspected cases (AR=14%) and isolated Aeromonas hydrophila from three stools of 15 cases. Students who ate in cafeteria A were more likely to be ill compared to those eating in other places (relative risk [RR]:3.1, 95% confidence interval [CI]:2.0-4.8). The cohort study implicated cold cucumber (RR:2.6, 95% CI:2.0-3.3) and houttuynia dishes (RR:1.8, 95% CI: 1.4-2.3). Environmental investigation showed that vegetables were washed in polluted water from a tank close to the sewage ditch, then left at 30 °C for two hours before serving. The Escherichia coli count of the tank was well above the standard for drinking-water. This outbreak of Aeromonas hydrophila was most probably caused by salad ingredients washed in contaminated tank water. We recommended enhancing training of foodhandlers, ensuring tanks and sewerage systems comply with appropriate standards and adequate monitoring of drinking-water sources.

Trace-back and trace-forward tools developed ad hoc and used during the STEC O104:H4 outbreak 2011 in Germany and generic concepts for future outbreak situations.

The Shiga toxin-producing Escherichia coli O104:H4 outbreak in Germany in 2011 required the development of appropriate tools in real-time for tracing suspicious foods along the supply chain, namely salad ingredients, sprouts, and seeds. Food commodities consumed at locations identified as most probable site of infection (outbreak clusters) were traced back in order to identify connections between different disease clusters via the supply chain of the foods. A newly developed relational database with integrated consistency and plausibility checks was used to collate these data for further analysis. Connections between suppliers, distributors, and producers were visualized in network graphs and geographic projections. Finally, this trace-back and trace-forward analysis led to the identification of sprouts produced by a horticultural farm in Lower Saxony as vehicle for the pathogen, and a specific lot of fenugreek seeds imported from Egypt as the most likely source of contamination. Network graphs have proven to be a powerful tool for summarizing and communicating complex trade relationships to various stake holders. The present article gives a detailed description of the newly developed tracing tools and recommendations for necessary requirements and improvements for future foodborne outbreak investigations.

Pressure Inactivation of Enteric Viruses in a Seafood Salad-Like Product

High pressure processing (HPP) is a nonthermal processing technology that can inactivate foodborne viruses. This study assessed the protective effects of food components on virus inactivation by HPP in a seafood salad model. Virus-inoculated seafood samples (cod, shrimp, tuna, and clams) with or without mayonnaise were pressure-treated at 5°C. The seafood salad provided a protective effect on HPP inactivation compared to cell culture medium. Inactivation in seafood salad varied greatly due to the complex nature of the food matrix. When seafood salad ingredients were isolated, mayonnaise alone had a 2.0-log10 PFU/g protective effect for all viruses, unlike albumin, which did not affect virus inactivation, providing some insight into the roles individual ingredients may play on HPP inactivation of viruses in foods.

Assessment of Vitamin and Carotenoid Concentrations of Emerging Food Products: Edible Microgreens

Microgreens (seedlings of edible vegetables and herbs) have gained popularity as a new culinary trend over the past few years. Although small in size, microgreens can provide surprisingly intense flavors, vivid colors, and crisp textures and can be served as an edible garnish or a new salad ingredient. However, no scientific data are currently available on the nutritional content of microgreens. The present study was conducted to determine the concentrations of ascorbic acid, carotenoids, phylloquinone, and tocopherols in 25 commercially available microgreens. Results showed that different microgreens provided extremely varying amounts of vitamins and carotenoids. Total ascorbic acid contents ranged from 20.4 to 147.0 mg per 100 g fresh weight (FW), while β-carotene, lutein/zeaxanthin, and violaxanthin concentrations ranged from 0.6 to 12.1, 1.3 to 10.1, and 0.9 to 7.7 mg/100 g FW, respectively. Phylloquinone level varied from 0.6 to 4.1 μg/g FW; meanwhile, α-tocopherol and γ-tocopherol ranged from 4.9 to 87.4 and 3.0 to 39.4 mg/100 g FW, respectively. Among the 25 microgreens assayed, red cabbage, cilantro, garnet amaranth, and green daikon radish had the highest concentrations of ascorbic acids, carotenoids, phylloquinone, and tocopherols, respectively. In comparison with nutritional concentrations in mature leaves (USDA National Nutrient Database), the microgreen cotyledon leaves possessed higher nutritional densities. The phytonutrient data may provide a scientific basis for evaluating nutritional values of microgreens and contribute to food composition database. These data also may be used as a reference for health agencies' recommendations and consumers' choices of fresh vegetables.

A group level validation of the supercombinatorality property: Finding high-quality ingredient combinations using pairwise information

This study tested the principle of supercombinatorality, i.e. that food combinations (of more than two items) that are fully compatible on a pairwise basis are more compatible than combinations that are not fully compatible pairwise. Previous work has shown this to hold for salad ingredient combinations predicted for individuals, but this has not yet been tested for groups. This study extended the previous findings to group data, and in a different product system, namely pizza toppings. Purchase intent responses to pairs of 25 different pizza toppings were collected and used to predict pizzas (with 1–6 toppings) that would appeal to the entire group. Results showed purchase interest to be higher for the predicted pizzas than for non-predicted pizzas supporting the supercombinatorality principle. The study demonstrates that food product developers can use consumer-driven data and a graph theoretic approach to screen large numbers of potential food combinations in order to predict potentially successful combinations and to do so in a highly cost-efficient manner.

Outbreak of powdery mildew caused by Erysiphe heraclei on Pleurospermum kamtschaticum in Korea

Pleurospermum kamtschaticum , family Apiaceae, is a perennial herb used as a salad ingredient and also as a traditional medicine in Asia (Cho et al., 2004). It has been widely planted in private gardens for personal consumption at …

대형 양식당 음식에 대한 미생물학적 위해분석

The purpose of this study was to microbiologically evaluate common foods and preparation processes in three large (over 100 pyeong) western-style restaurants in Daegu. Microbiological testing was conducted for pathogens including E. coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, E. coli O157:H7, Vibrio parahaemolyticus, and Bacillus cereus, as well as total plate count and coliforms. Food samples selected for testing represent common menu items and preparation processes. These samples included: 1) hamburger steak (cooking process), 2) mashed potatoes (reheating process), and 3) salad (non-heating process). The results showed that E. coli and S. aureus were detected in the raw ground beef used to prepare hamburger steak, but they were not detected after cooking at 82～86℃, 10 min. Microbiological quality of the mashed potatoes was better after reheating than during storage in a refrigerator after cooking. Total plate count and coliforms increased, and E. coli was detected in the salad ingredients stored in the refrigerator before serving. In order to serve foods of good microbiological safety and quality in western-style restaurants, standard cooking and reheating temperatures must be maintained during the cooking and reheating processes, and sanitation standard operating procedures must be followed for washing and storage of non-heated and refrigerated menu items.

Microbiological Safety of Sandwiches from Hospitals and Other Health Care Establishments in the United Kingdom with a Focus on Listeria monocytogenes and Other Listeria Species

In the United Kingdom between 1999 and 2004, there were four outbreaks of Listeria monocytogenes infection associated with sandwiches purchased from or provided in hospitals. Elderly or immunocompromised individuals and pregnant women are particularly vulnerable to infection; therefore, the focus of this study was on sandwiches served in health care establishments. Of 3,249 sandwich samples collected between April 2005 and March 2006, 3.3% were of unsatisfactory microbiological quality because of high levels of Enterobacteriaceae (2.0%; ≥104 CFU/g for sandwiches not containing salad), Escherichia coli (0.8%; ≥102 CFU/g), Staphylococcus aureus (0.6%; ≥102 CFU/g), and/or Listeria spp. (0.1%; two samples with L. welshimeri at 1.8 × 102 and 7.4 × 103 CFU/g and one sample with L. seeligeri at 1.8 × 103 CFU/g). Overall, 7.6% of sandwiches were contaminated with Listeria spp. L. monocytogenes was detected in 2.7% (88) of samples: 87 samples at <10 CFU/g and 1 sample at 20 CFU/g. More frequent contamination with Listeria spp. and L. monocytogenes was found in sandwiches collected from hospital cafeterias, shops, or wards and in sandwiches stored and/or displayed at temperatures higher than 8°C. The presence of Listeria spp. and L. monocytogenes also was associated with sandwiches that (i) were supplied from outside the establishment, (ii) were prepacked, (iii) had a main sandwich filling of poultry meat, or (iv) contained salad ingredients, soft cheese, and/or mayonnaise. Control of L. monocytogenes in sandwich manufacturing and within health care establishments is essential to minimize the potential for consumption of this bacterium at levels hazardous to health. The findings from this study support the proposal that manufacturers supplying sandwiches to health care establishments should follow the British Sandwich Association recommended guidelines of complete absence of L. monocytogenes in sandwiches at the point of production.

Comparison of the Microflora on Organically and Conventionally Grown Spring Mix from a California Processor

Considerable speculation has occurred concerning the potential for higher numbers of foodborne pathogens on organically grown produce compared with produce not grown organically. The microflora composition of spring mix or mesclun, a mixture of multiple salad ingredients, grown either by organic or conventional means was determined. Unwashed or washed spring mix was obtained from a commercial California fresh-cut produce processor who does not use manure in their cultivation practices. Fifty-four samples of each type of product were supplied over a 4-month period. Analysis included enumeration of total mesophiles, psychrotrophs, coliforms, generic Escherichia coli, lactic acid bacteria, yeasts, and molds. In addition, spring mix was analyzed for the presence of Salmonella and Listeria monocytogenes. The mean populations of mesophilic and psychrotrophic bacteria, yeasts, molds, lactic acid bacteria, and coliforms on conventionally grown spring mix were not statistically different (P > 0.05) from respective mean populations on organically grown spring mix. The mean population of each microbial group was significantly higher on unwashed spring mix compared with the washed product. Of the 14 samples found to contain E. coli, eight were from nonwashed conventional spring mix, one was from washed conventional spring mix, and four were from nonwashed organic spring mix. Salmonella and L. monocytogenes were not detected in any of the samples analyzed.

Southern Blight of Jerusalem Artichoke Caused by Sclerotium rolfsii in California.

Jerusalem artichoke or sunchoke (Helianthus tuberosus) is a specialty vegetable that is grown commercially in California. The fleshy tubers are harvested and used as a fresh salad ingredient or cooked vegetable. During 2003, field plantings of Jerusalem artichoke in coastal California (Santa Cruz County) showed symptoms of an unfamiliar disease. Initial symptoms consisted of wilting of new shoots and leaves followed by browning and collapse of all foliage. Crown and lower stem tissues turned tan to brown. In advanced stages of the disease, crown and stem tissues were colonized internally and externally by white, cottony mycelium. Tan, spherical sclerotia that measured approximately 1 mm in diameter formed on the surfaces of the affected crowns and stems. Mycelia and sclerotia also grew on the soil adjacent to infected plants. Isolations from symptomatic crowns, mycelia, and sclerotia produced colonies that were identified as Sclerotium rolfsii. Pathogenicity was tested using two methods that included sclerotial inocula collected from five isolates grown on potato dextrose agar plates. With the first method, sclerotia of each isolate were applied to sets of tubers (10 tubers per isolate) prior to planting tubers into a soilless, peat moss-based medium in pots. With the second method, 3-week-old potted plants were inoculated by placing sclerotia of each isolate adjacent to stem tissue that was 3 cm below the surface of the soilless medium. Noninoculated controls were included for both methods. All plants were incubated in a greenhouse at 21 to 24°C. For the first method, by the third week after planting, 10 to 40% of plants did not emerge because the tubers were rotted and decayed. For the plants that did emerge, wilting of foliage and browning of crown and stem tissue occurred approximately 6 weeks after planting and by 10 weeks, all plants were diseased. S. rolfsii was reisolated from all necrotic tuber, crown, and stem tissues. For the second method, disease symptoms and signs of the pathogen occurred 5 weeks after inoculation and by week 10, 75% of test plants were symptomatic. S. rolfsii was again reisolated from all necrotic tuber, crown, and stem tissues. Symptoms were not observed on any of the noninoculated plants. To my knowledge, this is the first report of southern blight of Jerusalem artichoke in California. This disease has been reported on Jerusalem artichoke in several southern U.S. states (1,2). The two inoculation methods demonstrated that the pathogen could infect propagation organs (tubers) and also emergent stems of this host.

Focus-group Sessions Suggest both Kids and Adults Enjoy Fresh Carrots

Focus-group Sessions Suggest both Kids and Adults Enjoy Fresh Carrots

Survival and Detection of Shigella flexneri in Vegetables and Commercially Prepared Salads

The normal bacterial microflora of 4 commercially prepared salads (coleslaw, crab salad, carrot salad, and potato salad) and 3 vegetables (green pepper, onion, and cabbage) were evaluated. Twenty-eight species of bacteria, including potential pathogens, were isolated. The foods were artificially inoculated with an avirulent mutant strain of Shigella flexneri 5 (pHS1059) to develop a method for the rapid detection of Shigella spp. Bacteria were separated from insoluble and particulate salad ingredients by filtration through shark skin filter paper and by low speed centrifugation. S. flexneri survived at 4 degrees C in all salads for at least 11 days and up to 20 days in crab salad. The polymerase chain reaction (PCR), using primers for amplification of a 118-base pair DNA fragment from the virulence-associated spa region, present in all Shigella spp., was used to detect S. flexneri in filtrates from salads inoculated with S. flexneri 5 (pHS1059). DNA was amplified from all of the artificially contaminated salads and vegetables except green pepper. After 3-5 days of storage, the PCR also amplified S. flexneri DNA from salads that had been enriched with nutrients to increase the number of bacteria. Green peppers contained a PCR inhibitory substance that was attenuated by dilution and enrichment before the PCR. No amplification of DNA was observed in foods to which S. flexneri had not been added.

Microbial Evaluation of Vegetable Ingredients in Salad Bars

Vegetable salad ingredients (lettuce, tomatoes, broccoli, and cauliflower) purchased from three grocery-store deli operations were analyzed for total plate count, coliforms, yeasts, and molds. The temperature of the vegetable ingredients was measured at the time of purchase and the pH was measured on all samples within one-half hour after purchase. In the second phase, fresh broccoli was processed into florets, inoculated with E. coli ATCC 23742, and subjected to three washing treatments.The temperature of the salad ingredients ranged from 5.1°C to 18.9°C. The pH ranges for the vegetables were broccoli, 5.46 to 6.39; cauliflower, 5.82 to 6.65; lettuce, 4.92 to 6.38; and tomatoes, 3.30 to 4.47. The total aerobic count for the vegetables ranged from 5.51 to 6.63 log CFU/g. Coliforms on the vegetables ranged from 4.89 to 6.30 log CFU/g. Yeasts and molds were found on all vegetables. The results of the study indicate that the temperature conditions and pH ranges for the broccoli, cauliflower, and lettuce could support microbial growth. The pH range of the tomatoes was below 4.6, but if contaminated and added to low acid foods, the tomatoes may also act as a vehicle for microbial contamination.When a chlorine wash solution was used, it slightly reduced the aerobic microbial load on previously inoculated broccoli and reduced the coliform population of the broccoli by approximately one log unit.

An Environmental Intervention to Increase Fruit and Salad Purchases in a Cafeteria

Background. This study explored the hypothesis that consumption of fruit and salad in a cafeteria setting would increase if the variety of offerings was increased and their price reduced. Method. Food purchases in a cafeteria setting were observed during 3 weeks of baseline observation, 3 weeks of intervention, and 3 weeks of return to baseline conditions. Intervention consisted of doubling the number of fruit choices, increasing salad ingredient selections by three, and reducing the price of both fruit and salad by 50%. The primary outcome measures in the study were daily sales of fruit and salad as assessed by cash register receipts. Results. Fruit and salad purchases increased threefold in the intervention period compared to those in the nonintervention periods. Women and those trying to control their weight were most likely to make these nutritious food choices. Conclusion. Results of this study support the argument that increasing the number of nutritious food choices and making them more attractive economically may be important to changing food choice behavior. Further exploration of the practical application of the concept is recommended.

Effect of Processing Conditions on the Microflora of Fresh-Cut Vegetables

Surveys were made of commercial processing lines used to prepare fresh-cut vegetables such as chopped salad ingredients, carrot sticks, and cauliflower florets. Washing and chlorinated water dips only partially removed the microorganisms that were intrinsic to the vegetables. Major sources of in-plant contamination were the shredders used to prepare chopped lettuce and coleslaw. Gram-negative rods were the predominant microflora with species of Pseudomonas being most numerous; many were psychrotrophic. Only low numbers of lactic acid bacteria and fungi were recovered.

Lectins in the United States diet: a survey of lectins in commonly consumed foods and a review of the literature

Plant lectins or phytohemagglutinins possess potent in vivo biological activities. Some, primarily of the family Leguminosae, have been shown to have deleterious nutritional effects. Little information exists, however, regarding the prevalence of lectins or the specific foods that contain lectins in the United States diet. In the present study the edible parts of 29 of 88 foods tested, including common salad ingredients, fresh fruits, roasted nuts, and processed cereals were found to possess significant lectin-like activity as assessed by hemagglutination and bacterial agglutination assays. Based on this survey and a review of the literature we conclude that dietary exposure to plant lectins is widespread. The spectrum of nutritional consequences of such exposure remains to be determined.

Breeding for Disease Resistance in Cucurbits

Members of the Cucurbitaceae are among the important and widespread plants that supply man's food and fiber. Cucurbits are not as important on a world basis as are cereals and legumes, but, from the tropics to the milder portions of the temperate zone, they serve as a source of carbohydrates, as dessert and salad ingredients, and as pickles. Some cucurbits are used as pot­ tery, baskets, insulation, and oil filters. The cultivated cucurbits have needed man for survival since bona fide specimens of the wild counterparts of the cultivated species have apparently never been collected. Although there are about 90 genera and 750 species in the family Cucur­ bitaceae, only 6 genera and 12 species are cultivated by man. These genera and species include watermelon (Citrullus); cucumber, muskmelon, and gherkin (Cucumis); dish-rag and sponge gourds (Luffa); white-flowered gourd (Lagenaria); squashes, marrow, pumpkin, and figleaf gourd (Cucur­ hila); and chayote (Sechium). All the species are frost-sensitive. Within each species there is a wide assortment of sizes, shapes, color variants, flesh tex­ tures, flavors, etc (62). The use of resistant varieties is a simple, effective, and economical means of controlling plant disease (45). A large number of disease resistance fac­ tors have been incorporated into cultivated cucurbits, particularly during the past 30 years. Associated with this has been the development of specific desir­ able horticultural characteristics. These two objectives are inseparable, as it is a bounteous yield of attractive, high quality fruits that is demanded by the consumer. In the present era, cucurbits are being produced commercially in areas where they could not be produced previously because of disease; vari­ eties with resistance to one disease have been replaced by varieties with resis­ tance to many diseases; disease resistance has been a major factor in develop­ ment of mechanized harvesting; the high cost of disease control has been re­ duced; disease epidemics have been curtailed; and the use of resistant culti­ vars has diminished hazards and pollution resulting from use of potentially dangerous fungicides. It is with the theme of a breakthrough this discussion is concerned.

Electrochemical oxidation of benzene to quinone

American wintergreen (Gaultheria procumbens L.), asparagus (Asparagus officinalis), baby corn (Zea maize var. crassa), broccoli (Brassica oleracea var. italica), celery (Apium graveolens), dandelion (Taraxacium officinale Wig.), Florence fennel (Foeniculum officinale D.C.), globe artichoke (Cynara scolymus L.), kohlrabi (Brassica oleracea var. gongylodes), oca (Oxalis tuberosa Molina), and parsnip (Pastinaca sativa L.) are grouped as stem type salad vegetables because they are often consumed raw as salad before taking major meal and act as a base for other salad ingredients. These crops for salad purpose are widely cultivated in home gardens almost round the year under favorable conditions comparatively at closer spacing for keeping them succulent and crisp. Besides providing minerals, vitamins and phytochemicals essentially required by human body, they also improve texture, flavor, palatability, and digestibility of other foods. These crops also have the medicinal properties and best fitted for household remedies for several human ailments. Most of them are best suited as intercrop in many fruit crops.

Solid carbon dioxide

American wintergreen (Gaultheria procumbens L.), asparagus (Asparagus officinalis), baby corn (Zea maize var. crassa), broccoli (Brassica oleracea var. italica), celery (Apium graveolens), dandelion (Taraxacium officinale Wig.), Florence fennel (Foeniculum officinale D.C.), globe artichoke (Cynara scolymus L.), kohlrabi (Brassica oleracea var. gongylodes), oca (Oxalis tuberosa Molina), and parsnip (Pastinaca sativa L.) are grouped as stem type salad vegetables because they are often consumed raw as salad before taking major meal and act as a base for other salad ingredients. These crops for salad purpose are widely cultivated in home gardens almost round the year under favorable conditions comparatively at closer spacing for keeping them succulent and crisp. Besides providing minerals, vitamins and phytochemicals essentially required by human body, they also improve texture, flavor, palatability, and digestibility of other foods. These crops also have the medicinal properties and best fitted for household remedies for several human ailments. Most of them are best suited as intercrop in many fruit crops.