Cold Plasma Inactivation of Salmonella in Prepackaged, Mixed Salads Is Influenced by Cross-Contamination Sequence

2017 ◽  
Vol 80 (12) ◽  
pp. 2132-2136 ◽  
Author(s):  
Sarah M. Hertrich ◽  
Glenn Boyd ◽  
Joseph Sites ◽  
Brendan A. Niemira
Keyword(s):  
Shelf Life ◽  
Corona Discharge ◽  
Cold Plasma ◽  
Food Products ◽  
Plate Count ◽  
Cross Contamination ◽  
Plastic Container ◽  
Peptone Water ◽  
Plasma Corona ◽  
Cherry Tomatoes

ABSTRACT Customer demand for convenient food products has led to an increased production of prepackaged and ready-to-eat food products. Most of these products rely mainly on surface disinfection and other traditional approaches to ensure shelf life and safety. Novel processing techniques, such as cold plasma, are currently being investigated to enhance the safety and shelf life of prepacked foods. The purpose of this study was to determine the effects of cold plasma corona discharge on the inactivation of Salmonella on prepackaged, tomato-and-lettuce mixed salads. Two different inoculation methods were evaluated to address cross-contamination of Salmonella from cherry tomatoes to lettuce and vice versa. In separate studies, a sample of either cherry tomatoes (55 g) or romaine lettuce (10 g) was inoculated with a Salmonella cocktail (6.93 ± 0.99 log CFU/mL), placed into a commercial polyethylene terephthalate plastic container, and thoroughly mixed together with its noninoculated counterpart. Mixed salads were allowed to dry in a biosafety cabinet for 1 h. Samples were treated with 35 kV cold plasma corona discharge inside plastic containers for 3 min. Samples were stomached and serially diluted in buffered peptone water and then were plated onto aerobic plate count Petrifilm and incubated for 18 h at 37°C. When lettuce was the inoculated counterpart, log kill of Salmonella was significantly greater on tomatoes (0.75 log CFU/g) compared with lettuce (0.34 log CFU/g) (P = 0.0001). Salmonella was reduced on mixed salad only when lettuce was the inoculated counterpart (0.29 log CFU/g) (P = 0.002). Cold plasma can kill Salmonella in a prepackaged mixed salad, with efficacy dependent on the nature of contamination, direction of transfer, and the surface topography of the contaminated commodity.

Use of Cold Plasma To Inactivate Escherichia coli and Physicochemical Evaluation in Pumpkin Puree

2018 ◽  
Vol 81 (11) ◽  
pp. 1897-1905 ◽  
Author(s):  
L. C. O. SANTOS ◽  
A. L. V. CUBAS ◽  
E. H. S. MOECKE ◽  
D. H. B. RIBEIRO ◽  
E. R. AMANTE
Keyword(s):  
Escherichia Coli ◽  
Corona Discharge ◽  
Cold Plasma ◽  
Treatment Time ◽  
Physicochemical Characteristics ◽  
Carotenoid Content ◽  
E Coli ◽  
Process Gas ◽  
Total Carotenoid Content ◽  
Plasma Corona

ABSTRACT This work aimed to study the pumpkin puree processing by cold plasma corona discharge as an alternative to heat treatment to reduce Escherichia coli contamination and evaluate physicochemical alterations, using argon (Ar) as the process gas. The treatment time to verify E. coli inactivation was between 2 and 20 min, while physicochemical alterations were analyzed at 5, 10, 15, and 20 min. Cold plasma corona discharge technology to inactivate E. coli proved to be promising, reaching 3.62 log cycles of reduction at 20 min of treatment. The inactivation kinectics showed a tendency of higher decrease with time. Physicochemical characteristics indicate that plasma induces a decrease of pH; however, there is an indication that process gases have an important role and react with the environment and procedure reactive species. This technology may reduce the total carotenoid content of pumpkin puree and in color, mainly the a* parameter, which showed great reduction.

scholarly journals Effects of Atmospheric Plasma Corona Discharge on Agrobacterium tumefaciens Survival

2021 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
Yulia Lazra ◽  
Bharath Gandu ◽  
Irina Dubrovin Amar ◽  
Efrat Emanuel ◽  
Rivka Cahan
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Corona Discharge ◽  
Membrane Permeability ◽  
Cell Size ◽  
Cold Plasma ◽  
Bacterial Eradication ◽  
Liquid Environment ◽  
Initial Concentration ◽  
Plasma Corona ◽  
The Impact

Soil-borne pathogenic microorganisms are known to cause extensive crop losses. Agrobacterium tumefaciens, a member of the Proteobacteria, causes the neoplastic crown gall disease in plants. Plant protection is mainly based on toxic chemicals that are harmful to the environment. The use of cold atmospheric-pressure plasma is an attractive method for microbial eradication. Its antimicrobial mechanism includes the formation of large quantities of reactive oxygen species (ROS). The advantages of eradicating bacteria using cold plasma are not needed for chemicals, short treatment, and environmental temperatures. This study examined the impact of plasma corona discharge exposure on A. tumefaciens viability, membrane permeability, relative cell size, and ROS formation. The results showed that 90 s of plasma exposure led to a reduction by four orders of magnitude when the initial concentration was 1 × 107 CFU/mL and in a dry environment. When the initial concentration was 1 × 106 CFU/mL, 45 s of exposure resulted in total bacterial eradication. In a liquid environment, in an initial concentration of 2.02 × 106 CFU/mL, there was no complete bacterial eradication even at the most prolonged examined exposure (90 s). The influence of plasma treatment on the membrane permeability of A. tumefaciens, and their possible recovery, were analyzed using flow cytometer analysis using propidium iodide (PI). When the plasma-treated bacteria were suspended in Luria–Bertani (LB) (rich medium), the PI-positive count of the plasma-treated bacteria after two hours was 12 ± 3.9%. At the 24th hour, this percentage was only 1.74 ± 0.6%, as the control (0.7 ± 0.1%). These results may indicate the repair of the plasma-treated bacteria that were suspended in LB. At the 24th hour, the relative cell size of the treated bacteria shifted to the right, to ~3 × 104 forward side scatter (FSC), about 0.5-fold higher than the untreated cells. Measurement of the ROS showed that the intracellular fluorescence of the 90-s plasma-treated cells led to significant fluorescence formation of 32 relative fluorescence units (RFU)/cell (9 × 104 fold, compared to the nontreated cells). This study showed that cold plasma is a useful method for A. tumefaciens eradication. The eradication mechanism involves ROS generation, membrane permeability, and changes in cell size.

scholarly journals In-package atmospheric pressure cold plasma treatment of cherry tomatoes

2014 ◽  
Vol 118 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Nrusimha Nath Misra ◽  
Kevin M. Keener ◽  
Paula Bourke ◽  
Jean-Paul Mosnier ◽  
Patrick J. Cullen
Keyword(s):  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Cold Plasma ◽  
Cherry Tomatoes

scholarly journals Effect of Humidity-Controlled Dehydration on Microbial Growth and Quality Characteristics of Fresh Wet Noodles

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 844
Author(s):  
Jun-Jie Xing ◽  
Dong-Hui Jiang ◽  
Zhen Yang ◽  
Xiao-Na Guo ◽  
Ke-Xue Zhu
Keyword(s):  
Shelf Life ◽  
Microbial Growth ◽  
Treatment Time ◽  
Positive Influence ◽  
Quality Characteristics ◽  
Plate Count ◽  
Cooking Properties ◽  
Total Plate Count ◽  
Different Temperatures

Humidity-controlled dehydration (HCD) was innovatively applied in this paper to control the growth of microorganisms in fresh wet noodles (FWN). Effects of HCD treatment with different temperatures (40, 60 or 80 °C), relative humidity (RH, 50%, 70% or 90%) and treatment time (5–32 min) on the total plate count (TPC), the shelf-life, and qualities of FWN were investigated. The results showed that HCD reduced the initial microbial load on the fresh noodles and extended the shelf-life up to 14–15 days under refrigeration temperature (10 °C). A 1.39 log10 CFU/g reduction for the initial TPC was achieved after HCD treatment at the temperature of 60 °C and RH of 90%. HCD with higher RH had a more positive influence on quality improvement. The L* values, the apparent stickiness, and the cooking properties of the noodle body were improved by HCD while good sensory and texture quality of noodles were still maintained after the dehydration process.

Processing and Value Addition of Bamboo Shoots for Utilization as Food Products

2020 ◽  
Vol 27 (1) ◽  
pp. 27-32
Author(s):  
Ashok Kumar Pandey ◽  
Keyword(s):  
Shelf Life ◽  
Value Added ◽  
Cost Effective ◽  
Nutrient Content ◽  
Food Products ◽  
Value Addition ◽  
Mineral Contents ◽  
Bamboo Shoots ◽  
Processed Products ◽  
Edible Products

Bamboo shoots being low in fat, high in dietary fiber and rich in mineral contents have been consumed traditionally by the people world over. Besides nutrients it also contains some anti-nutrients e.g. cyanogens. Due to seasonal availability of bamboo shoots, processing for reducing anti-nutrients in raw shoots while keeping nutrients intact and enhancement of shelf life of the value added products assume great significance for its utilization. This paper focuses on post harvest processing and value addition of bamboo shoots for its utilization as food products. Juvenile bamboo shoots of Bambusa bambos, B. tulda, Dendrocalamus asper and D. strictus were collected and processed, by boiling in brine solution, to remove the anti-nutrients (cyanogen). A simple, efficient and cost effective processing method for bamboo shoots was developed. This method significantly reduces the amount of cyanogens and retains considerable amount of nutrients and thus may be utilized for processing of bamboo shoots. Different value added edible products viz. chunks or bari (by adding pulses), pickle, sauce and papad (by adding potato) were prepared. All products were good in taste and texture. Nutritional analysis was done to determine the shelf life of the products. The nutrient content of processed products (chunks, sauce, pickle and papad) showed a gradual decrease and need to be consumed within 6 months from the date of making. However, in case of papad the carbohydrate content did not decrease much but the taste was not acceptable after 8 months. Whereas, in case of pickles, even nutrient content decreased but the product was acceptable even after two years after preparation as it was good in taste and texture. Thus, processing and value addition practices can be considered as key to the future of sustainable management of bamboo resources because they not only provide quality edible products but also enable harvesters/collectors to get better income opportunities.

scholarly journals UMUR SIMPAN SAMBAL PARI (Dasyatis Sp.) ASAP YANG DIKEMAS JAR PADA BEBERAPA CARA PEMASAKAN DENGAN METODE PENDUGAAN ACCELERATED SHELF-LIFE TESTING (ASLT)

2020 ◽  
Vol 13 (2) ◽  
pp. 118
Author(s):  
Dian Rachmawanti Affandi ◽  
Adhitya Pitara Sanjaya ◽  
Santi Rahma Mardiana
Keyword(s):  
Shelf Life ◽  
Plate Count ◽  
Life Testing ◽  
Total Plate Count

<p>Penambahan ikan pari asap pada pembuatan sambal dapat menjadi alternatif pengolahan ikan pari asap dan menghasilkan sambal dengan cita rasa khas. Selama penyimpanan, sambal mengalami penurunan mutu secara mikrobiologi serta menyebabkan perubahan aroma dan timbulnya asam pada sambal sehingga produk ditolak oleh konsumen. Penelitian ini bertujuan untuk mengetahui pengaruh variasi cara kualitas sensoris, kimiawi, dan mikrobiologis sambal ikan pari asap kemasan <em>jar </em>kaca selama penyimpanan, umur simpan sambal, serta menentukan cara pemasakan untuk memperpanjang umur simpan sambal. Pengemasan menggunakan <em>jar </em>kaca dan variasi cara pemasakan pada sambal ikan pari asap dilakukan untuk mencegah penurunan mutu. Variasi cara pemasakan yang dilakukan yaitu pemasakan kering (P1), pemasakan setengah kering (P2), dan pemasakan kering dengan penambahan minyak setelah pemasakan (P3). Selanjutnya, untuk memenuhi standar keamanan pangan dan sebagai jaminan mutu dilakukan pendugaan umur simpan sambal ikan pari asap menggunakan metode ASLT model Arrhenius yang memiliki waktu pengujian relatif singkat dengan ketepatan dan akurasi tinggi.  Parameter yang diuji adalah sensoris aroma, total asam tertitrasi (TAT), dan <em>total plate count </em>(TPC). Penurunan mutu sambal diamati pada penyimpanan suhu 35˚C, 45˚C dan 55˚C selama 48 jam dengan waktu pengamatan setiap 12 jam sekali. Berdasarkan hasil peneli tian, tiga variasi cara pemasakan sambal ikan pari asap memiliki penurunan mutu yang berbeda-beda selama penyimpanan. Umur simpan sambal ikan pari asap kemasan <em>jar</em> kaca menurut parameter kritis TAT pada cara pemasakan kering (P1) pada suhu 30˚C adalah 165,95 jam. Pada variasi pemasakan setengah kering (P2), umur simpan sambal pada suhu 30˚C adalah 155,04 jam. Pada variasi pemasakan kering dengan penambahan minyak (P3), umur simpan sambal pada suhu 30˚C adalah 197,96 jam. Variasi pemasakan kering dengan penambahan minyak goreng setelah pemasakan merupakan cara terbaik untuk memperpanjang umur simpan sambal ikan pari asap kemasan <em>jar </em>kaca.</p><p> </p><br clear="ALL" /><p> </p>

scholarly journals KEBERADAAN MIKROBA PADA BAKSO IKAN ASAP CAIR, YANG DIKEMAS DALAM RETORTABLE POUCH, DIPASTEURISASI DAN DISIMPAN PADA TEMPERATUR RUANG

2016 ◽  
Vol 4 (2) ◽  
pp. 85
Author(s):  
Margani Luyuani Rohana ◽  
Siegfried Berhimpon ◽  
Joyce CV Palenewen
Keyword(s):  
Shelf Life ◽  
Water Content ◽  
Experimental Method ◽  
Room Temperature ◽  
Plate Count ◽  
E Coli ◽  
Existing Problems ◽  
Liquid Smoke ◽  
Total Plate Count ◽  
And Storage

A research has been done to assess the presence of microbes and the shelf life of fish balls dipped in liquid smoke, packed in retortable pouch, pasteurized, and stored at room temperature. The method used in this research is an experimental method that revealed the facts based on existing problems through hypothesis testing. Parameters assessed are Total Plate Count (TPC), total Salmonella, total coliforms and E. coli, total vibrio, water content, and pH. Fish balls were pasteurized in 85ºC and stored in room temperature for 0, 3, 6, and 9 days, and were pasteurized at 100°C and storage in room temperature for 0, 9, 18, and 27 days. The results shown that all pathogen were negative, but based on Indonesian standard (SNI 01-7266-1-2006) especially TPC value, fish balls were packaged in retortable pouch and without pasteurized is no longer acceptable for consumption after 3 days of storage, and fish balls were packaged in retortable pouch and pasteurized at 85ºC no longer acceptable for consumed after 6 days of storage. While the fish balls are packaged in retortable pouch and pasteurized at 100°C is no longer acceptable for consumed after 18 days of storage.Keyword: Retortable Pouch, Pasteurization, Pathogens.  Penelitian ini bertujuan untuk mengetahui keberadaan mikroba dan daya awet bakso ikan yang direndam dalam asap cair dan dikemas dalam Retortable pouch, dipasteurisasi, dan disimpan pada temperatur ruang. Metode yang digunakan dalam penelitian ini adalah metode eksperimen untuk menguji hipotesa. Parameter yang diamati yaitu Angka Lempeng Total (ALT), Salmonella, total koliform dan E.coli, total vibrio, analisa kadar air, dan nilai pH. Bakso ikan asap cair yang dipasteurisasi pada 85ºC, disimpan pada temperatur ruang selama 0, 3, 6, dan 9 hari, dan yang dipasteurisasi pada 100ºC, disimpan pada temperatur ruang selama 0,9,18, dan 27 hari. Hasil penelitian menunjukkan bahwa bakso ikan yang dikemas dalam Retortable pouch, tanpa dipasteurisasi sudah tidak layak lagi untuk dikonsumsi setelah penyimpanan 3 hari, dan bakso ikan yang dikemas dalam Retortable pouch dan dipasteurisasi pada 85ºC sudah tidak layak lagi untuk dikonsumsi setelah penyimpanan 6 hari. Bakso ikan yang dikemas dalam Retortable pouch, dan dipasteurisasi pada 100ºC nanti tidak layak lagi dikonsumsi setelah penyimpanan 18 hari.Kata Kunci: Kemasan Retortable Pouch, Pasteurisasi, Patogen.

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