Isolation and Identification of Lipolytic Microorganisms Found on Rough Rice from Two Growing Areas

1978 ◽  
Vol 41 (1) ◽  
pp. 28-30 ◽  
Author(s):  
ANTHONY J. DeLUCCA ◽  
STEPHEN J. PLATING ◽  
ROBERT L. ORY

Rice bran and whole brown rice are currently underutilized because free fatty acids are formed from rice oil during storage. Rough rice from two growing areas was tested for presence of lipolytic microorganisms that could release these fatty acids. Approximately 10% of the total bacterial plate count (4 × 106/g for Louisiana and 12 × 106/g for the Arkansas rice samples) were lipolytic. Upon testing, most were classified as nonsaccharolytic, alkali-producing pseudomonads. The average mold plate count for the Louisiana sample was 2 × 103 colony forming units (cfu)/g and 5 × 103 cfu/g for the Arkansas sample. All molds isolated showed various amounts of lipolytic action, as determined by the size of the lipolytic zone. The molds were generally isolated more from the Louisiana than from the Arkansas rice. Alternaria and Helminthosporium species, the most prevalent molds, were found in all samples.

2020 ◽  
Vol 36 (6) ◽  
pp. 983-993
Author(s):  
Fatima S Rodriguez ◽  
Paul R Armstrong ◽  
Elizabeth B Maghirang ◽  
Kevin F Yaptenco ◽  
Erin D Scully ◽  
...  

HighlightsNIR spectroscopy detects quantitative and qualitative levels of chlorpyrifos-methyl residues in bulk rice.Levels of chlorpyrifos-methyl residues in bulk rice can be differentiated at 78% to 100% correct classification.Important NIR wavelengths for chlorpyrifos-methyl residue detection were identified.NIR spectroscopy can be used to detect maximum residue levels of chlorpyrifos-methyl pesticide in rice.Abstract. A rapid technique that uses near-infrared reflectance (NIR) spectroscopy for simultaneous qualitative and quantitative determination of the presence of varying concentrations of chlorpyrifos-methyl in bulk samples of rough, brown, and milled rice was established. Five rice varieties, free of pesticides, obtained from RiceTec Inc. and USDA-ARS Arkansas experimental field were used as rough rice samples and also processed to obtain corresponding brown and milled rice. Rice samples were treated with StorcideTM II containing varying levels of the active ingredient, chlorpyrifos-methyl: 0, 1.5, 3, 6, 9, and 12 ppm for rough rice, 0, 0.75, 1.5, 3, 4.5, and 6 ppm for brown rice, and 0, 0.1, 0.2, 0.4, 0.6, and 0.8 ppm for milled rice. Concentrations of chlorpyrifos-methyl were verified using gas chromatography-mass spectrometry analyses. A commercial NIR spectrometer (950-1650 nm wavelength range) was used to obtain spectra of bulk samples. Using partial least squares analysis for quantitative analysis, independent validation showed that chlorpyrifos-methyl residues in rough, brown, and milled rice are predictable with R2 ranging from 0.702 to 0.839 and standard error of prediction (SEP) of 1.763 to 2.374 for rough rice, R2 ranging from 0.722 to 0.800 and SEP of 0.953 to 1.168 for brown rice, and R2 ranging from 0.693 to 0.789 and SEP of 0.131 to 0.164 for milled rice. For qualitative analysis obtained using discriminant analysis, rough rice samples with concentrations of 0, 1.5, and 3 ppm pooled as low pesticide level (LPL) is distinguishable to 6, 9, and 12 ppm which were pooled as high pesticide level (HPL). Similarly, for brown and milled rice, the lower three concentrations pooled as LPL is distinguishable from the higher three concentrations pooled as HPL. Independent validation showed overall correct classifications ranging from 77.8% to 92.6% for rough rice, 79.6% to 88.9% for brown rice, and 94.4% to 100% for milled rice. Keywords: Food safety, Grain quality, NIR spectroscopy, Pesticide residue, Rice.


2019 ◽  
Vol 35 (4) ◽  
pp. 361-368
Author(s):  
Hu Shi ◽  
Terry J. Siebenmorgen

Abstract.The angle of repose (AoR) is a primary characteristic determining the flowablity of grains and thus is an important property for designing rice handling and storage facilities. The aim of this study was to evaluate the AoR of contemporary rice cultivars grown in the United States. An apparatus was constructed to measure both the emptying and piling AoR of rice samples. The effect of rice cultivars (pureline and hybrid), rice types (long-, medium-, and short-grain rice), rice forms (rough, brown, head, and broken milled rice), and moisture content on the AoR of rice were evaluated. Results indicated that all of these factors significantly affected the AoR of rice. The piling AoR was significantly less than the emptying AoR. Hybrid rice cultivars tended to have greater AoR than purelines, which was attributed to the pubescence characteristic of their hulls. The emptying AoR and piling AoR of tested long-grain rough rice cultivars at 12% to 21% moisture content were in the range of 32.7° to 39.7° and 29.6° to 36.9°, respectively.Increasing the moisture content of long-grain rough rice led to greater AoR, possibly due to increased cohesion of rice kernels. Long-grain rough rice cultivars had slightly lesser AoR than those of medium- and short-grain rice cultivars. Among all tested rice forms, brown rice had the least AoR. Head and broken milled rice had approximately the same AoR as rough rice. Keywords: Angle of repose, Bridging, Flowablity, Friction, Rice.


Author(s):  
J Aquarista Ingratubun ◽  
Frans G Ijong ◽  
Hens Onibala

Food fermentation is one of various food processing techniques that has sufficient benefits of nutrition values, and also contains lactic acid bacteria which potentially inhibit pathogenic bacteria, thus prolong shelf life of  products. Bakasang is a traditional fermented food from North Sulawesi since many years ago. Reported research of bakasang previously had described that lactic acid bacteria was the dominant isolates and therefore current research  aimed to isolate and identify the lactic acid bacteria which associated during fermentation day 1 and day 15, respectively. Raw materials used were 5 kg intestine and liver of skipjack brought from local market Bersehati Manado. The intestine and liver of skipjack were washed and smashed and mixed with 10% salt  and 5% rice  from weight of the samples and then filled into bottle to be fermented for 15 days. Every 3 days (1,3,6,9,12,15), the samples were collected and analyzed for total lactic acid bacteria by using Total Plate Count Method on de Mann Rogosa Sharpe Agar after incubation at 37°C for 24 h. The colonies  grown were transferred to Tryptic Soy Broth and followed by streaking them on Tryptic Soy Agar and the free growing colony on agar medium were isolated into slant agar which were used for biochemical test such as Gram’s staining, motility test, catalase test, oksidase test, H2S test, IMVIC test (Indole, Methyl Red, Voges Proskauer, Citrate) and carbohydrate fermentation. The results showed that Lactobacillus sp., Bacillus sp., Eubacterium sp., and Bifidobacterium sp. All these four bacteria were distributed from day 1 to day 15 of the fermentation process© Fermentasi bahan pangan merupakan salah satu dari sekian banyak teknik pengolahan makanan yang mempunyai banyak manfaat dari kualitas gizi, mengandung bakteri asam laktat sehingga menghambat bakteri patogen sehingga daya simpan lebih panjang. Bakasang merupakan makanan fermentasi tradisional masyarakat Sulawesi Utara yang sudah ada sejak lama. Penelitian yang telah dilakukan terhadap bakasang menghasilkan informasi bahwa terdapat bakteri asam laktat pada bakasang sehingga menjadi tujuan untuk mengisolasi dan identifikasi bakteri asam laktat selama proses fermentasi 1-15 hari. Bahan baku bakasang ialah jeroan (usus dan hati) ikan cakalang Katsuwonis pelamis sebanyak 5 kg yang diambil dari pasar Bersehati Manado. Sampel jeroan dibersihkan kemudian dihancurkan, ditambahkan garam 10% dan nasi 5% kemudian difermentasi selama 15 hari dengan mengambil tiap-tiap sampel setiap 1, 3, 6, 9, 12, dan 15 untuk dihitung jumlah bakteri asam laktat dengan menggunakkan metode Total Plate Count pada media de Mann Rogosa Sharpe Agar dan koloni yang tumbuh di tumbuhkan  kembali pada media Tryptic Soy Broth  dan digores kembali pada media Tryptic Soy Agar, koloni yang tumbuh digores pada media slant agar yang selanjutnya diidentifikasi bakteri asam laktat berdasarkan uji biokimia yaitu uji pewarnaan Gram, uji motility, uji katalase, uji oksidase, uji H2S dan uji IMVIC (Indole, MethylRed, Voges Proskauer, Citrate). Hasil menunjukkan bahwa selama proses fermentasi berlangsung terdapat 4 genera bakteri asam laktat sesuai yaitu Lactobacillus sp., Bacillus sp., Eubacterium sp., dan Bifidobacterium sp., ke 4 genera ini tersebar pada fermentasi hari 1 sampai hari ke 15©


Fitoterapia ◽  
2012 ◽  
Vol 83 (3) ◽  
pp. 490-499 ◽  
Author(s):  
Pei Gao ◽  
Tomoya Hirano ◽  
Zhiqing Chen ◽  
Tadashi Yasuhara ◽  
Yoshihiro Nakata ◽  
...  

1988 ◽  
Vol 51 (1) ◽  
pp. 53-55 ◽  
Author(s):  
F. A. KHAYAT ◽  
J. C. BRUHN ◽  
G. H. RICHARDSON

A total of 256 cheese samples were analyzed for coliform plate count using violet red bile agar and for an impedance count using BactometerR Coliform Medium with a correlation coefficient between methods of R=−.91. Fifty-four percent of the samples contained 102 to 107 colony forming units/gram (CFU/g). The highest counts were in cream and fresh cheese products. When 27 Cheddar cheese samples were inoculated with from 102 to 107 CFU of Escherichia coli/g a correlation of R=−.97 was found between methods. Two hundred of the cheese samples were analyzed for Staphylococcus aureus using Baird-Parker medium and impedance count using BactometerR S.aureus Medium. Five samples (2%) contained over 103 CFU/g. The strains isolated were coagulase-positive. When 34 samples of cheese were inoculated with 102 to 107 CFU of staphylococci/g, the correlation between the plate and impedance method was R=0.98.


1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.


2021 ◽  
Vol 12 ◽  
Author(s):  
M. L. Jane Weitzel ◽  
Christina S. Vegge ◽  
Marco Pane ◽  
Virginia S. Goldman ◽  
Binu Koshy ◽  
...  

Probiotics are live microorganisms that confer a health benefit to the host when administered in adequate amounts. This definition links probiotic efficacy to microbial viability. The current gold standard assay for probiotic potency is enumeration using classical microbiology plating-based procedures, yielding results in colony-forming units (CFU). One drawback to plating-based procedures is high variability due to intrinsic and extrinsic uncertainties. These uncertainties make comparison between analytical procedures challenging. In this article, we provide tools to reduce measurement uncertainty and strengthen the reliability of probiotic enumerations by using analytical procedure lifecycle management (APLM). APLM is a tool that uses a step-by-step process to define procedure performance based on the concept that the reportable value (final CFU result) must be fit for its intended use. Once the procedure performance is defined, the information gathered through APLM can be used to evaluate and compare procedures. Here, we discuss the theory behind applying APLM and give practical information about its application to CFU enumeration procedures for probiotics using a simulated example and data set. Data collected in a manufacturer’s development laboratory is included to support application of the concept. Implementation of APLM can lead to reduced variability by identifying specific factors (e.g., the dilution step) with significant impact on the variability and providing insights to procedural modifications that lead to process improvement. Understanding and control of the analytical procedure is improved by using these tools. The probiotics industry can confidently apply the information and analytical results generated to make decisions about processes and formulation, including overage requirements. One benefit of this approach is that companies can reduce overage costs. More reliable procedures for viable cell count determinations will improve the quality evaluation of probiotic products, and hence manufacturing procedures, while ensuring that products deliver clinically demonstrated beneficial doses.


2021 ◽  
Vol 16 (2) ◽  
pp. 132-143
Author(s):  
Selvia Tharukliling ◽  
Lilik Eka Radiati ◽  
Imam Thohari ◽  
Agus Susilo

This study aims to determine the antimicrobial activity of red fruit paste against Staphylococcus aureus FNCC-0047 and Eschericia coli FNCC-0091 by using ethanol and n-hexane as well as the total plate count value of the patty with red fruit paste added on different observations day. The concentration of paste extract for antimicrobial activity test was 6.25%, 12.5%, 25%, 50%. The calculation of the total value of the burger patty plate is calculated on the 3rd, 7th and 14th d with the red fruit paste content in the formula as much as 0%, 5%, 10%, 15%. The results showed that the fatty acids of red fruit paste were dominated by oleic acid and linoleic acid, which are unsaturated fatty acids and palmitic acid, which are saturated fatty acids. The yield of red fruit paste in n-hexane solvent was higher than ethanol solvent. There was a significant difference (P <0.05) from the use of different solvents to the mean clear zone of the two bacteria tested. The antibacterial activity shown by the ethanol extract and n-hexane extract of red fruit paste was in the inactive category at the 6.12% level, the moderate category at the 12.5% to 25% level and the strong category at the 50% level. There was a significant difference (P <0.05) from the total microbial value in each treatment where the higher the red fruit paste content in the patty, the lower the total microbial value found on each d of observation. The use of red fruit paste at a level of 10% to 15% can withstand the rate of microbial growth


2005 ◽  
Vol 68 (1) ◽  
pp. 120-125 ◽  
Author(s):  
ANTHONY C. SALES ◽  
TAKUMI YOSHIZAWA

Mold counts and Aspergillus section Flavi populations in rice and its by-products from the Philippines were examined. The average mold counts of rough rice, brown rice, and locally produced polished rice were 4.1 × 103, 1.0 × 103, and 1.1 × 103 CFU/g, respectively. Average Aspergillus section Flavi counts of the same samples were 3.0 × 102, 1.1 × 102, and 2.6 × 102 CFU/g, respectively. Twenty-seven percent of mold isolates from rough rice, polished rice, and brown rice were section Flavi spp., 31% of which were toxigenic. No section Flavi isolates were obtained from imported rice samples from Thailand and Vietnam. Aspergillus section Flavi was also isolated from rice hull, rice bran, and settled dust from rice milling operations. Toxigenic isolates of both Aspergillus flavus and Aspergillus parasiticus were present in at least one sample of each type of rice and rice by-product except settled dust. Aflatoxins produced in vitro by the isolates ranged from &lt;1 μg/kg to 6,227 μg/kg. A. flavus isolates produced only B aflatoxins, whereas A. parasiticus isolates produced both B and G aflatoxins. Although total mold counts of Philippine rice and its by-products are within tolerable limits, the establishment of maximum limits in counts of potentially aflatoxigenic species in foods and feeds is important because the mere presence of toxin producers is considered a possible risk factor. The results of this research illustrate the need for strict monitoring of rice during both storage and marketing, especially in warm and humid seasons when infestation and consequent production of aflatoxins by Aspergillus section Flavi is expected.


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