ResearchPad - boiling Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Nutritional and physicochemical characteristics of purple sweet corn juice before and after boiling]]> Sweet corn juice is becoming increasingly popular in China. In order to provide valuable health-related information to consumers, the nutritional and physicochemical characteristics of raw and boiled purple sweet corn juices were herein investigated. Sugars, antinutrients, total free phenols, anthocyanins, and antioxidant activity were analyzed by conventional chemical methods. The viscosity and stability of juices were determined by Ubbelohde viscosity meter and centrifugation, respectively. Boiling process could elevate viscosity, stability and sugar content, and reduce antinutrients, total free phenols, anthocyanins, and antioxidant activity in corn juice. In addition, short time boiling efficiently reduced the degradation of anthocyanins during subsequent refrigeration. The content of amino acids, vitamin B1/B2 and E were detected by High Performance Liquid Chromatography. Gas Chromatography Mass Spectrometry was used for the analysis of fatty acids and aroma compounds. Several aroma compounds not previously reported in corn were identified, including 1-heptanol, 2-methyl-2-butenal, (Z)-3-nonen-1-ol, 3-ethyl-2-methyl-1,3-hexadiene, and 2,4-bis(1,1-dimethylethyl)phenol. Interestingly, the boiling process had no apparent effect on the amino acids profile, but it caused a 45.8% loss of fatty acids in the juice by promoting the retention of fatty acids in the corn residue. These results provide detailed information that could be used for increasing consumers’ knowledge of sweet corn juice, further development of sweet corn juice by food producers, and maize breeding programs.

<![CDATA[Release of aluminium and thallium ions from uncoated food contact materials made of aluminium alloys into food and food simulant]]>

In order to investigate the release of aluminium ions from food contact materials, three different types of uncoated aluminium menu trays for single use were tested with the foodstuffs sauerkraut juice, apple sauce and tomato puree, as well as with the food simulants 5 g/L citric acid solution and artificial tap water. To mimic a consumer relevant exposure scenario, the aluminium trays were studied using time and temperature gradients according to the Cook & Chill method, also taking into account storage time at elevated temperatures during the delivery period. The release of aluminium was found to exceed the specific release limit (SRL) of 5 mg aluminium per kilogram of food specified by the Council of Europe by up to six times. Furthermore, a release of thallium was also detected unexpectedly.

Kinetic studies showed a comparable behaviour in the release of aluminium, manganese and vanadium as components of the aluminium alloy itself. In contrast, thallium could be identified as a surface contaminant or impurity because of an entirely different kinetic curve. Kinetic studies also allowed activation energy calculations.

Additional camping saucepans were tested as an article for repeated use. In three subsequent release experiments with citric acid (5 g/L), artificial tap water and tomato puree as benchmark foodstuffs, the results were comparable to those of the uncoated wrought alloy aluminium trays.

<![CDATA[Bioactive Compounds in Potato Tubers: Effects of Farming System, Cooking Method, and Flesh Color]]>

We investigated the effect of cultivation system (conventional or organic), cooking method, and flesh color on the contents of ascorbic acid (AA) and total phenolics (TPs), and on total antioxidant activity (Trolox equivalents, TE) in Solanum tuberosum (potato) tubers. The research material, consisting of 4 potato cultivars, was grown in experimental fields, using organic and conventional systems, at the experimental station in 2012 and 2013. The analysis showed that organically grown potatoes with creamy, light yellow, and yellow flesh had significantly higher TPs than did potatoes grown conventionally. Flesh color and cooking method also affected AA. The greatest losses of AA occurred in yellow-fleshed potatoes grown conventionally and cooked in the microwave; such losses were not observed in potatoes grown organically. A dry cooking method (baking in a microwave) increased the TP contents in potatoes by about 30%, regardless of the flesh color and the production system. TE was significantly higher in organically grown potatoes (raw and cooked in a steamer) than in conventionally grown potatoes. TE and AA contents showed a significant positive correlation, but only in potatoes from the organic system [R2 = 0.686]. By contrast, the positive correlation between TE and TPs was observed regardless of the production system. Therefore, we have identified the effects of farming system, cooking method, and flesh color on the contents of bioactive compounds in potato tubers.

<![CDATA[Boiling histotripsy lesion characterization on a clinical magnetic resonance imaging-guided high intensity focused ultrasound system]]>


High intensity focused ultrasound (HIFU) is a non-invasive therapeutic technique that can thermally ablate tumors. Boiling histotripsy (BH) is a HIFU approach that can emulsify tissue in a few milliseconds. Lesion volume and temperature effects for different BH sonication parameters are currently not well characterized. In this work, lesion volume, temperature distribution, and area of lethal thermal dose were characterized for varying BH sonication parameters in tissue-mimicking phantoms (TMP) and demonstrated in ex vivo tissues.


The following BH sonication parameters were varied using a clinical MR-HIFU system (Sonalleve V2, Philips, Vantaa, Finland): acoustic power, number of cycles/pulse, total sonication time, and pulse repetition frequency (PRF). A 3×3×3 pattern was sonicated inside TMP’s and ex vivo tissues. Post sonication, lesion volumes were quantified using 3D ultrasonography and temperature and thermal dose distributions were analyzed offline. Ex vivo tissues were sectioned and stained with H&E post sonication to assess tissue damage.


Significant increase in lesion volume was observed while increasing the number of cycles/pulse and PRF. Other sonication parameters had no significant effect on lesion volume. Temperature full width at half maximum at the end of sonication increased significantly with all parameters except total sonication time. Positive correlation was also found between lethal thermal dose and lesion volume for all parameters except number of cycles/pulse. Gross pathology of ex vivo tissues post sonication displayed either completely or partially damaged tissue at the focal region. Surrounding tissues presented sharp boundaries, with little or no structural damage to adjacent critical structures such as bile duct and nerves.


Our characterization of effects of HIFU sonication parameters on the resulting lesion demonstrates the ability to control lesion morphologic and thermal characteristics with a clinical MR-HIFU system in TMP’s and ex vivo tissues. We demonstrate that this system can produce spatially precise lesions in both phantoms and ex vivo tissues. The results provide guidance on a preliminary set of BH sonication parameters for this system, with a potential to facilitate BH translation to the clinic.

<![CDATA[Exfoliated MoS2 in Water without Additives]]>

Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants and other funtionalization agents. Pure water should be an ideal solvent, however, it is generally believed, based on solubility theories that stable dispersions of water could not be achieved and systematic studies are lacking. Here we describe the use of water as a solvent and the stabilization process involved therein. We introduce an exfoliation method of molybdenum disulfide (MoS2) in pure water at high concentration (i.e., 0.14 ± 0.01 g L−1). This was achieved by thinning the bulk MoS2 by mechanical exfoliation between sand papers and dispersing it by liquid exfoliation through probe sonication in water. We observed thin MoS2 nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of the nanosheets were around 200 nm, the same range obtained in organic solvents. Electrophoretic mobility measurements indicated that electrical charges may be responsible for the stabilization of the dispersions. A probability decay equation was proposed to compare the stability of these dispersions with the ones reported in the literature. Water can be used as a solvent to disperse nanosheets and although the stability of the dispersions may not be as high as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable.

<![CDATA[Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh]]>

Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets) near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs) to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98), type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00), and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00) exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a cholera endemic population suggests a possible role for highly targeted interventions. Studies with cluster designs in areas with strong spatial clustering of exposures should increase sample size to account for the correlation of these exposures.

<![CDATA[Comparison of Boiling and Robotics Automation Method in DNA Extraction for Metagenomic Sequencing of Human Oral Microbes]]>

The rapid improvement of next-generation sequencing performance now enables us to analyze huge sample sets with more than ten thousand specimens. However, DNA extraction can still be a limiting step in such metagenomic approaches. In this study, we analyzed human oral microbes to compare the performance of three DNA extraction methods: PowerSoil (a method widely used in this field), QIAsymphony (a robotics method), and a simple boiling method. Dental plaque was initially collected from three volunteers in the pilot study and then expanded to 12 volunteers in the follow-up study. Bacterial flora was estimated by sequencing the V4 region of 16S rRNA following species-level profiling. Our results indicate that the efficiency of PowerSoil and QIAsymphony was comparable to the boiling method. Therefore, the boiling method may be a promising alternative because of its simplicity, cost effectiveness, and short handling time. Moreover, this method was reliable for estimating bacterial species and could be used in the future to examine the correlation between oral flora and health status. Despite this, differences in the efficiency of DNA extraction for various bacterial species were observed among the three methods. Based on these findings, there is no “gold standard” for DNA extraction. In future, we suggest that the DNA extraction method should be selected on a case-by-case basis considering the aims and specimens of the study.

<![CDATA[Effect of processing on composition changes of selected spices]]>

The present investigation was conducted to study the true retentions of α-tocopherol, tocotrienols and β-carotene in crown daisy, unripe hot pepper, onion, garlic, and red pepper as affected by various domestic cooking methods, those were, boiling, baking, stir-frying, deep-frying, steaming, roasting, and microwaving. Fatty acid compositions were determined by GC, and HPLC were used for quantification of α-tocopherol, tocotrienols, and β-carotene. True retentions of α-tocopherol in cooked foods were as follows: boiling (77.74–242.73%), baking (85.99–212.39%), stir-frying (83.12–957.08%), deep-frying (162.48–4214.53%), steaming (45.97–179.57%), roasting (49.65–253.69%), and microwaving (44.67–230.13%). Similarly for true retention of β-carotene were: boiling (65.69–313.75%), baking (71.46–330.16%), stir-frying (89.62–362.46%), deep-frying (178.22–529.16%), steaming (50.39–240.92%), roasting (73.54–361.47%), and microwaving (78.60–339.87%).

<![CDATA[Raspberry Ketone Analogs: Vapour Pressure Measurements and Attractiveness to Queensland Fruit Fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)]]>

The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Q-fly), is a major horticultural pest in Eastern Australia. Effective monitoring, male annihilation technique (MAT) and mass trapping (MT) are all important for control and require strong lures to attract flies to traps or toxicants. Lure strength is thought to be related in part to volatility, but little vapour pressure data are available for most Q-fly lures. Raspberry ketone (4-(4-hydroxyphenyl)-2-butanone) and analogs that had esters (acetyl, difluoroacetyl, trifluoroacetyl, formyl, propionyl) and ethers (methyl ether, trimethylsilyl ether) in replacement of the phenolic group, and in one case also had modification of the 2-butanone side chain, were measured for their vapour pressures by differential scanning calorimetry (DSC), and their attractiveness to Q-fly was assessed in small cage environmentally controlled laboratory bioassays. Maximum response of one category of compounds, containing both 2-butanone side chain and ester group was found to be higher than that of the other group of compounds, of which either of 2-butanone or ester functionality was modified. However, linear relationship between vapour pressure and maximum response was not significant. The results of this study indicate that, while volatility may be a factor in lure effectiveness, molecular structure is the dominating factor for the series of molecules investigated.

<![CDATA[Use of Oral Cholera Vaccine and Knowledge, Attitudes, and Practices Regarding Safe Water, Sanitation and Hygiene in a Long-Standing Refugee Camp, Thailand, 2012-2014]]>

Oral cholera vaccines (OCVs) are relatively new public health interventions, and limited data exist on the potential impact of OCV use on traditional cholera prevention and control measures—safe water, sanitation and hygiene (WaSH). To assess OCV acceptability and knowledge, attitudes, and practices (KAPs) regarding cholera and WaSH, we conducted cross-sectional surveys, 1 month before (baseline) and 3 and 12 months after (first and second follow-up) a preemptive OCV campaign in Maela, a long-standing refugee camp on the Thailand-Burma border. We randomly selected households for the surveys, and administered questionnaires to female heads of households. In total, 271 (77%), 187 (81%), and 199 (85%) households were included in the baseline, first and second follow-up surveys, respectively. Anticipated OCV acceptability was 97% at baseline, and 91% and 85% of household members were reported to have received 1 and 2 OCV doses at first follow-up. Compared with baseline, statistically significant differences (95% Wald confidence interval not overlapping zero) were noted at first and second follow-up among the proportions of respondents who correctly identified two or more means of cholera prevention (62% versus 78% and 80%), reported boiling or treating drinking water (19% versus 44% and 69%), and washing hands with soap (66% versus 77% and 85%); a significant difference was also observed in the proportion of households with soap available at handwashing areas (84% versus 90% and 95%), consistent with reported behaviors. No significant difference was noted in the proportion of households testing positive for Escherichia coli in stored household drinking water at second follow-up (39% versus 49% and 34%). Overall, we observed some positive, and no negative changes in cholera- and WaSH-related KAPs after an OCV campaign in Maela refugee camp. OCV campaigns may provide opportunities to reinforce beneficial WaSH-related KAPs for comprehensive cholera prevention and control.