scholarly journals Effect of moisture and temperature on the extrudate properties of milkfish (Chanos chanos) feed

2019 ◽  
Vol 66 (4) ◽  
Author(s):  
S. Syed Raffic Ali ◽  
K. Ambasankar ◽  
S. Balachandran ◽  
K. Ramachandran

The present study evaluated the effect of varying levels of moisture and temperature on the extrudate properties of the milkfish (Chanos chanos) feed containing 31.49% protein and 4.71% lipid. Two trials were conducted in a pilot scale twin screw extruder using 3 mm die. In the first trial, the effect of temperature on extrudate properties was studied at five different temperatures viz., 80-90, 90-100, 100-110, 110-120 and 120-130°C. The results revealed that the temperature levels of 100-110, 110-120 and 120-130°C resulted in significantly (p<0.05) lower bulk density (BD) of the extrudate than at 80-90 and 90-100°C. Significantly (p<0.05) lower water solubility index (WSI) was recorded at 100-110°C, while further increase in temperature failed to show further reduction in water solubility. The pellet durability index (PDI) and expansion ratio (ER) showed a non-significant difference among the extrudates at 100-110, 110-120 and 120-130°C. In the second trial, the effect of additional moisture on the extrudate was evaluated by including water at 20, 25, 30 and 35% and the results revealed that 30% moisture addition resulted in significantly (p<0.05) lower BD, WSI and PDI of the extrudate than the other levels. The highest moisture level of 35% led to difficulty in operation while the lower levels from 25% failed to produce floating pellets. Results of this study infers that 30% moisture addition and a temperature of 100-110°C is optimalfor production of water stable floating milk fish feeds.

2012 ◽  
Vol 06 (04) ◽  
pp. 361-369 ◽  
Author(s):  
Serdar Baglar ◽  
Adil Nalcaci ◽  
Mustafa Tastekin

ABSTRACTObjective: The aim of this study was to examine the effect of temperature on fluoride uptake by enamel specimens from a 0.05% NaF-fluoridated mouthrinse (Oral-B Advantage; Oral-B Laboratories, Newbridge, UK).Methods: Enamel specimens were prepared from extracted human maxillary central incisors. A fluoride-specific ion electrode was used to measure the uptake from a 2 ppm fluoride solution containing 50.0 mL of distilled water, total ion strength adjustment buffer, and fluoridated rinse at 3 different temperatures (room temperature, 25°C; human body temperature, 37°C; hyper-fever temperature, 43°C). One-way analysis of variance and least significant difference were used to assess intragroup and intergroup differences (P<.05).Results: The study found that both the amount and the rate of fluoride uptake increased significantly with increase in temperature. This effect was particularly noticeable at 43°C.Conclusions: The temperature of the NaF mouthrinse may easily and safely be increased beyond room temperature by placing a container of the NaF mouthrinse in a bowl of hot water, allowing greater fluoride penetration into the enamel from the mouthrinse when used at home as a routine prophylactic agent. (Eur J Dent 2012;6:361-369)


Parasitology ◽  
1968 ◽  
Vol 58 (3) ◽  
pp. 641-651 ◽  
Author(s):  
J. Barrett

The development of the free-living infective larvae of a homogonic strain Strongyloides ratti is described.The larvae develop only between 15 and 34 °C. Transfer experiments show the temperature block to be in the preparation for the second moult.Within the temperature range 15–34 °C, increasing the temperature speeds up the rate of development of all the larval stages equally, the Q10 for development being 2·5.The maximum percentage development occurs at 20 °C. The percentage development is highest in faeces–peat culture (95% development at 20 °C), whilst the percentage development in charcoal and vermiculite cultures is about the same (75% development at 20 °C.).Larvae grown on charcoal cultures are larger than those grown on vermiculite, which are larger than those grown on peat. No significant difference was found in the length:oesophagus and length:width ratios or in the variability of larvae grown at different temperatures or on different culture media.Different worm densities in the cultures of from 2000 to 10000 larvae per g of culture did not affect either the size of the infective larve or the percentage development.The optimum temperature for survival is 15 °C. Worms grown at 20 °C lived longer than worms grown at any other temperature. There was no evidence of temperature adaptation by the larvae.The infective larvae are positively thermotactic, and show maximum activity at 37 °C.I should like to thank my supervisor, Dr Tate, for his advice and encouragement. The work was carried out during the tenure of a Medical Research Council Scholarship.


2019 ◽  
Vol 13 (2) ◽  
pp. 103-108
Author(s):  
Serdar Akarsu ◽  
Suleyman Kutalmış Buyuk ◽  
Ahmet Serkan Kucukekenci

Background. The temperature might affect the physical and mechanical properties of adhesive materials by reducing the polymerization rate. The present study aimed to evaluate the effect of temperature on the shear bond strength of metallic orthodontic brackets using various adhesive resin systems. Methods. Extracted human premolar teeth were randomly assigned to 8 groups (n=10) for bonding with the two available orthodontics adhesive systems (Transbond XT and NeoBond) at different temperatures: refrigeration temperature (4°C), room temperature (20°C), human body temperature (36°C) and high temperature (55°C). The shear bond strength (SBS) test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. The adhesive remnant index (ARI) was assigned to the fractured orthodontic brackets. Data were analyzed with one-way ANOVA, post hoc Tukey tests and independent t-test. Results. Transbond XT exhibited higher SBS values compared to Neobond at all the tested temperatures; however, a statistically significant difference was not observed (P>0.05). The SBS results were minimum at 4°C and maximum at 36°C in both the adhesive groups (P<0.05). Conclusion. Pre-heating orthodontic adhesives up to the body temperature prior to bonding the brackets in orthodontic treatment increased the bond strength of orthodontic brackets.


2020 ◽  
Vol 15 (1) ◽  
pp. 572-579
Author(s):  
Aldona Sobota ◽  
Piotr Zarzycki ◽  
Anna Wirkijowska ◽  
Zbigniew Rzedzicki ◽  
Agnieszka Pawlas

AbstractThe purpose of the present study was to examine the extrusion-cooking process of cereal blends with addition of hatchery waste (HW). The effect of HW addition on the physical properties and chemical composition of the extrudates was examined. The share of the HW in blends with corn meal was variable in the range of 5–30%. The study was conducted using a counter-rotating twin-screw extruder (L:D ratio 12:1, screw speed 75 rpm, die diameters 3 mm × 6 mm, profile of barrel temperature 120/140/180/180/130°C, and material moisture 28%). Increase in the content of the HW from 5 to 30% reduced the expansion ratio, pellet durability index, water absorption index, and water solubility index of the extrudates. The microstructure of the extrudates with HW addition is non-homogeneous; the areas with densely packed and adherent granules, interwoven with fibrous structures, can be observed. Increase in the share of HW leads to a lowering of the levels of crude fiber and total dietary fiber in the extrudates. Moreover, a significant increase in the content of protein, crude fat, and mineral elements such as calcium, sodium, magnesium, and iron was observed.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Naveen Vadukapuram ◽  
Clifford Hall ◽  
Mehmet Tulbek ◽  
Mary Niehaus

Milled flaxseed was incorporated (0–20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly(P≤0.05)different from the control. In general, no significant difference(P>0.05)in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5–10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 870
Author(s):  
Rubina Rumler ◽  
Denisse Bender ◽  
Sofia Speranza ◽  
Johannes Frauenlob ◽  
Lydia Gamper ◽  
...  

Due to climate change sorghum might gain widespread in the Western countries, as the grain is adapted to hot climate. Additionally sorghum contains a notable amount of health-promoting nutrients. However, Western countries do not have a long history of sorghum consumption, and thus little experience in processing it. Milling systems in these areas were mostly developed for wheat or rye milling. In the present work, the effectiveness of sorghum milling when using a stone and a roller milling system (pilot scale) was investigated as well as its impact on the chemical and physical properties of the obtained flour fractions and whole-grain flours. Results showed that both milling systems could be successfully adapted to producing chemically and physically distinct flour and bran fractions from the small sorghum kernels. Fractions with increased bran material that contained higher amounts of ash, protein, fat, total dietary fiber, and total phenolic content but less starch, showed enhanced water absorption indices and water solubility indices. Interestingly, no significant difference was found in the ash and fat content of the different fractions obtained from stone milling. Overall, the study provided information on the production and composition of distinct flour fractions, which offer a wider range of future food applications.


2011 ◽  
Vol 101 (8) ◽  
pp. 1013-1020 ◽  
Author(s):  
J. Diéguez-Uribeondo ◽  
H. Förster ◽  
J. E. Adaskaveg

Blossoms, leaves, fruit, and woody tissues of almond can be affected by anthracnose caused by Colletotrichum acutatum. Because the disease occurs throughout rainy spring seasons, the effect of temperature and wetness duration on disease development was evaluated in controlled studies. The lowest inoculum concentration where disease developed on leaves was 104 conidia/ml. Longer wetness durations were needed for leaves than for blossoms and disease increased linearly with increasing wetness durations. Inoculation temperature mainly affected final disease levels. Temperature during incubation affected the rate of disease development, while final disease levels were very similar at 10, 15, or 20°C. An analysis of covariance was performed to compare regressions of the effects of wetness and temperature on disease development for several almond cultivars. For blossom inoculations at 15°C in growth-chamber studies, a common slope model was statistically sufficient to describe all four cultivars. Cultivar Nonpareil (NP) had a significantly (P < 0.05) lower adjusted means at the midpoint than cultivars Carmel (CA), NePlus Ultra (NU), and Wood Colony (WC). For blossom inoculations at 20°C and for leaf inoculations at all temperatures evaluated, an unequal slope model was statistically justified for comparing regression lines. For blossoms, the slopes were significantly different (P < 0.05) for pair-wise comparisons of CA-NU, NU-WC, and NP-WC. For leaves, most of the cultivars responded differently to infection at different temperatures. Two of the pair-wise comparisons demonstrated unequal slopes at all three temperatures evaluated (i.e., NU-NP and NU-WC). Overall, for blossoms and leaves, NP was the least susceptible, NU was the most susceptible, and WC and CA showed an intermediate susceptibility. In field blossom and fruit studies, a common slope model was statistically sufficient to describe all four cultivars. NP had a significantly lower midpoint (i.e., was less susceptible) than CA or WC, whereas no significant difference (P > 0.1) occurred in comparisons between CA and WC.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 134
Author(s):  
Ana Isabel Galván ◽  
Alicia Rodríguez ◽  
Alberto Martín ◽  
Manuel Joaquín Serradilla ◽  
Ana Martínez-Dorado ◽  
...  

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.


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