scholarly journals Preservatives and neutralizing substances in milk: analytical sensitivity of official specific and nonspecific tests, microbial inhibition effect, and residue persistence in milk

2015 ◽  
Vol 45 (9) ◽  
pp. 1613-1618 ◽  
Author(s):  
Livia Cavaletti Corrêa da Silva ◽  
Ronaldo Tamanini ◽  
Juliana Ramos Pereira ◽  
Edson Antônio Rios ◽  
José Carlos Ribeiro Junior ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Microbial Growth ◽  
Raw Milk ◽  
Analytical Sensitivity ◽  
Detection Capability ◽  
Microbial Inhibition ◽  
Milk Adulteration ◽  
Microbial Growth Inhibition

<p>Milk fraud has been a recurring problem in Brazil; thus, it is important to know the effect of most frequently used preservatives and neutralizing substances as well as the detection capability of official tests. The objective of this study was to evaluate the analytical sensitivity of legislation-described tests and nonspecific microbial inhibition tests, and to investigate the effect of such substances on microbial growth inhibition and the persistence of detectable residues after 24/48h of refrigeration. Batches of raw milk, free from any contaminant, were divided into aliquots and mixed with different concentrations of formaldehyde, hydrogen peroxide, sodium hypochlorite, chlorine, chlorinated alkaline detergent, or sodium hydroxide. The analytical sensitivity of the official tests was 0.005%, 0.003%, and 0.013% for formaldehyde, hydrogen peroxide, and hypochlorite, respectively. Chlorine and chlorinated alkaline detergent were not detected by regulatory tests. In the tests for neutralizing substances, sodium hydroxide could not be detected when acidity was accurately neutralized. The yogurt culture test gave results similar to those obtained by official tests for the detection of specific substances. Concentrations of 0.05% of formaldehyde, 0.003% of hydrogen peroxide and 0.013% of sodium hypochlorite significantly reduced (P<0.05) the microbial counts in milk after 24 and 48h refrigeration. Formaldehyde and sodium hypochlorite remained detectable in milk after 48 and 24h of refrigeration, respectively; while hydrogen peroxide could not be detected after 24h. Official tests for the detection of milk fraud by the addition of preservatives and neutralizing substances present limitations and may be ineffective in detecting milk adulteration</p>

scholarly journals Detection of antibacterial residues in milk by HPLC-DAD and microbial inhibitor tests

2020 ◽  
Vol 38 (No. 1) ◽  
pp. 63-71
Author(s):  
Sofia Christoforidou ◽  
Eftychia Karageorgou ◽  
Maria Ioannidou ◽  
Evdoxios Psomas ◽  
Martha Maggira ◽  
...  
Keyword(s):  
Raw Milk ◽  
Hplc Method ◽  
Detection Sensitivity ◽  
Detection Capability ◽  
Milk Samples ◽  
Sheep Milk ◽  
Microbial Inhibition ◽  
Maximum Residue Levels ◽  
Array Detection ◽  
Residue Levels

The objective of this study was to assess the detection sensitivity of four commercial microbial inhibition assays (MIAs) in comparison with the results by High Pressure Liquid Chromatography with Diode Array Detection (HPLC-DAD) for residues of three tetracyclines, trimethoprim and sulfadiazine in fortified raw milk samples. MIAs showed fairly good results at detecting sulfadiazine residues, whereas concerning tetracyclines and trimethoprim residues, most of the kits showed insufficient results. HPLC analysis revealed high recoveries of examined compounds with detection limits below their respective maximum residue levels (MRLs). The HPLC method was validated determining linearity, accuracy, precision, detection capability and decision limit. Subsequently, both methods were used to monitor several cow and sheep milk samples for the presence of antibacterial agents. Results obtained showed that MIAs could be successfully used for the analysis of different milk types. However, milk spoilage which was observed in some cases could decrease the sensitivity of the kits, a fact that does not seem to influence the effectiveness of HPLC-DAD method.<br /><br />

The fate of aflatoxin in naturally contaminated corn during the ethanol fermentation

1979 ◽  
Vol 25 (8) ◽  
pp. 911-914 ◽  
Author(s):  
E. B. Lillehoj ◽  
A. Lagoda ◽  
W. F. Maisch
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Ethanol Fermentation ◽  
Potential Problem ◽  
Animal Feed ◽  
Ammonium Hydroxide ◽  
Spent Grains ◽  
Toxin Degradation

Corn naturally contaminated with aflatoxin was used as a substrate in the ethanol fermentation. Distribution of toxin in several process and recovery fractions was identified. Although little degradation of the mycotoxin occurred during fermentation, no toxin appeared in the distilled alcohol. As accumulation of toxin in spent grains represents a potential problem in use of the material as animal feed, several decontamination procedures were tested. Sodium hydroxide, ammonium hydroxide, sodium hypochlorite, and hydrogen peroxide were identified as efficient agents of toxin degradation.

Valorization of Seaweed: Using Brown Algae Waste in Papermaking

2021 ◽  
Author(s):  
Ana Moral ◽  
Roberto Aguado ◽  
Jose Amaya ◽  
Antonio Tijero ◽  
Menta Ballesteros
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Brown Seaweed ◽  
Primary Source ◽  
Sodium Perborate ◽  
Lipophilic Compounds ◽  
Dictyota Dichotoma ◽  
Reinforcing Material ◽  
Loss Of Strength

Abstract In this work, the brown alga Dictyota dichotoma was explored as a new reinforcing material for papermaking. Performing the typical chemical tests for cellulosic substrates on D. dichotoma evidenced large amounts of ethanol:benzene extractable substances (7.2%) and ashes, algae-specific results. Also, even if lipophilic compounds are removed, brown seaweed are not a primary source of fibers because it contains low proportion of cellulose. However, its elevated content of insoluble carbohydrates (51.4%) suggest there is some potential in association with conventional cellulosic pulps, as fibrous elements contribute to sheet forming and other components fill the spaces in the paper web without noteworthy loss of strength. Extraction was carried out with clean processes: hydrogen peroxide and mixtures (hydrogen peroxide-hydrochloric acid and hydrogen peroxide-sodium perborate), sodium hydroxide and sodium hypochlorite, always aiming for low reagent concentrations, in the range of 1-12%. The results show that sodium hydroxide and sodium hypochlorite were the treatments that lead to paper sheets with better structural and mechanical properties without further bleaching or refining, thus highlighting the suitability of these algae for papermaking applications.

Peroxide Test Strips Detect Added Hydrogen Peroxide in Raw Milk at Levels Affecting Bacterial Load

2014 ◽  
Vol 77 (10) ◽  
pp. 1809-1813 ◽  
Author(s):  
NICOLE H. MARTIN ◽  
ADAM FRIEDLANDER ◽  
ALLEN MOK ◽  
DAVID KENT ◽  
MARTIN WIEDMANN ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Bacterial Load ◽  
Raw Milk ◽  
The United States ◽  
Test Strips ◽  
Predicted Probability ◽  
Milk Adulteration ◽  
History Of ◽  
History Of Use

Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of &gt;90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2.

scholarly journals Use of hydrogen peroxide, citric acid and sodium hypochlorite as sanitizer for minimally processed table grapes

2018 ◽  
Vol 33 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Muharrem Ergun ◽  
Ezgi Dogan
Keyword(s):  
Hydrogen Peroxide ◽  
Citric Acid ◽  
Sodium Hypochlorite ◽  
Microbial Growth ◽  
Tap Water ◽  
Fungal Growth ◽  
Table Grape ◽  
Minimally Processed ◽  
Table Grapes ◽  
Grape Cultivars

The objective of this study was to explore two local table grape cultivars, one is white and the other one red colored, as a minimally processed produce, and to identify the most effective sanitizers (hydrogen peroxide, citric acid or sodium hypochlorite) to control microbial growth. The table grape cultivars indigenous to Elazig province of Turkey ‘Agin Beyazi’ and ‘Agin Kirmizisi’ were tested in the present experiment. Grape clusters were washed by dipping in tap water as control, in citric acid (20 g/L), with sodium hypochlorite (50 mg/L), or with hydrogen peroxide (20 g/L), solutions for 1 minute. Grape berries were then placed into PET clamshells and kept at 4 °C for 10 days. The berries were subject to quality assessments during the storage, and to total aerobic microbial and fungal count at the end. Washing with hydrogen peroxide- or sodium hypochlorite-diluted water was very effective controlling both aerobic microbial and fungal growth. Citric acid treatment however represented no significant effect on microbial growth. It is concluded that both hydrogen peroxide and sodium hypochlorite are strong sanitizers for table grapes tested, with no detection of undesirable effects.

scholarly journals Oxidation of Cellulose from Oil Palm Empty Fruit Bunch Using Hydrogen Peroxide in Alkaline Condition

2018 ◽  
Vol 8 (02) ◽  
pp. 51 ◽  
Author(s):  
Isroi Isroi ◽  
Adi Cifriadi
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Oil Palm ◽  
Visual Analysis ◽  
Alkaline Condition ◽  
Cellulose Content ◽  
Empty Fruit Bunch ◽  
Cellulose Oxidation ◽  
Oxidation Effect

There are growing interest to use cellulose as renewable material in order to replace non-renewable polymeric materials. Alteration and chemical modifications of the cellulose by oxidation is needed to improve its properties and functionality. The aim of this study was to evaluate oxidation effect of the cellulose from oil palm empty fruit bunch (OPEFB) using hydrogen peroxide in alkaline condition. Cellulose has been isolated and purified by sodium hydroxide method followed by sodium hypochlorite bleaching. The oxidation effect of the cellulose by hydrogen peroxide was investigated by component analysis of the lignocelluloses, visual analysis, physical and chemical properties. Fourier transform infrared spectroscopy was employed to evaluate the changes of functional groups. Digesting of the OPEFB by sodium hydroxide at temperature 160oC for 4 hours reduced lignin content from 22.58% to 16.60%, increase cellulose and hemicelluloses content from 60.76% to 73.87% and 25.86% to 30.95%, respectively. Treatment of the OPEFB pulp using sodium hypochlorite removed all residual lignin. Cellulose content was increased up to 90.86%. Degree of polymerization of the oxidized cellulose was reduced from 1997 to 658. Carboxyl groups of celluloses was significantly increased and confirmed by titration analysis. OPEFB cellulose fiber was damage and broken, meanwhile crystallinity of the cellulose was reduced.Keywords: cellulose, oxidation, oil palm empty fruit bunch, carboxyl group, crystallinity, physical properties Oksidasi Selulosa dari Tandan Kosong Kelapa Sawit menggunakan Hidrogen Peroksida dalam Kondisi BasaAbstrakPerhatian untuk memanfaatkan selulosa sebagai polimer terbarukan untuk menggantikan polimer tidak terbarukan mengalami peningkatan. Perubahan dan modifikasi kimia selulosa melalui proses oksidasi diperlukan untuk meningkatkan sifat dan fungsi selulosa. Penelitian ini bertujuan untuk mempelajari pengaruh oksidasi selulosa dari tandan kosong kelapa sawit (TKKS) menggunakan hidrogen peroksida dalam suasana basa. Selulosa diisolasi dan dimurnikan dengan metode natrium hidroksida dan dilanjutkan dengan pemutihan natrium hipoklorit. Efek oksidasi selulosa oleh hidrogen peroksida dievaluasi menggunakan analisis komponen lignoselulosa, analisis visual, sifat fisik dan kimia. Analisis spektroskopi inframerah (FTIR) digunakan untuk mengevaluasi perubahan gugus fungsional selulosa. Pemasakan TKKS dengan natrium hidroksida pada suhu160oC selama 4 jam mengurangi kandungan lignin dari 22,58% menjadi 16,60%, meningkatkan kandungan selulosa dari 60,76% menjadi 73,87% dan hemiselulosa dari 25,86% menjadi 30,95%. Perlakuan pulp TKKS menggunakan natrium hipoklorit menghilangkan semua sisa lignin. Kandungan selulosa meningkat hingga 90,86%. Oksidasi selulosa dengan hidrogen peroksida menurunkan derajat polimerisasi selulosa dari 1997 menjadi 658. Gugus karboksil selulosa meningkat secara signifikan dan dikonfirmasi dengan analisis titrasi. Analisis visual menunjukkan kerusakan serabut selulosa, sesuai dengan pengurangan kristalinitas selulosa.Kata kunci: selulosa, oksidasi, tandan kosong kelapa sawit, gugus karboksil, kristalinitas, sifat fisik 

Comparison of Acrylamide and Agar Gels by Freeze-Etching

1977 ◽  
Vol 35 ◽  
pp. 606-607
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Electron Microscope ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Chromic Acid ◽  
Distilled Water ◽  
Thin Sheets ◽  
Acid Cleaning ◽  
Agar Gels ◽  
Freeze Etching ◽  
Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

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