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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Expansionsmöjligheter hos Acheta domesticus : En studie om syrsmjölets påverkan på färg,textur, gillande och expansion i extruderadmajskrok. / Expandability of Acheta domesticus : A study on the effect of cricket flour on color, texture, liking and expansion in extruded corn puffs.

Andersson, Fredrik, Hansson, Mattias January 2020 (has links)
I takt med en ökande världspopulation ställs allt hårdare krav på primärproducenter att tillgodose råvaror i adekvata mängder. Forskning inom området är av stor vikt för att hitta nya hållbara källor för näringsämnen som exempelvis protein, eftersom produktionen i dagsläget för med sig många miljömässiga nackdelar. I samband med att EU godkänner insekter som livsmedel får fler upp ögonen för eventuella fördelar som de kan bidra med som råvara. Syftet med denna studien är att undersöka vilken påverkan tillsats av syrsmjöl har på färg, textur, gillande och expansion hos extruderad majskrok. Detta är ett steg i riktningen mot implementering av insekter i västerländsk kost. Genom att analysera vatten och proteinhalt i den extruderade produkten, samt mäta dess färg, textur, radiella expansion och gillande hos konsument kan insamlad data ställas mot varandra och eventuella korrelationer belysas. Resultatet från studien visar att vid högre andel syrsmjöl blir texturen kompaktare, expansionen mindre och en färgförändring sker åt det mörkare hållet. De prov med lägre andel tillsatt syrsmjöl, och därmed en bättre expansion, fick högst gillandepoäng på alla frågeställningar i ett konsumenttest. / In line with a growing world population, higher demands are put on primary producers to supply raw materials in adequate quantities. Research in the area is of great importance in finding new sustainable sources of nutrients such as protein, which presently brings with it many environmental disadvantages. As the EU approves insects as food, more people are becoming aware of potential benefits they can provide. The purpose of this report is to investigate the effect of the addition of cricket flour on the color, texture, liking and expansion of an extruded corn puff. This is a step towards the implementation of insects in the Western diet. By analyzing the water and protein content of the extruded product, as well as measuring its color, texture, radial expansion and consumer appreciation, collected data can be compared and any correlations can be shown. The results of the study show that with a higher proportion of cricket flour the texture becomes more compact, shows less expansion and a color change toward a darker tone. The samples with a lower proportion of added cricket flour, and thus a better expansion, received the highest points of liking on all the questions in the consumer test.
2

Sensorimotor integration and the role of the cercal system in the reproductive behavior of the cricket, Acheta domesticus

Snell, Lewis Casbeer. January 2005 (has links)
Thesis (Ph. D.)--Miami University, Dept. of Zoology, 2005. / Title from second page of PDF document. Includes bibliographical references (p. 100-108).
3

A Novel Insect Model To Study The Role Of Fragile X Mental Retardation Protein In Innate Immunity And Behavior

Sorrell, Mollie R. 26 July 2019 (has links)
No description available.
4

Sensorimotor Integration And The Role Of The Cercal System In The Reproductive Behavior Of The Cricket, <i>Acheta Domesticus</i>

Snell, Lewis Casbeer 05 August 2005 (has links)
No description available.
5

The maturation of the immune system and the effects of crowding and light stress during development on the immune function of the adult house cricket Acheta domesticus

Piñera, Angelica Vivas 21 August 2012 (has links)
No description available.
6

Phenolic characterization and bioactivity of microwave-assisted extracts from edible house crickets (Acheta domesticus)

Maria C Nino Bernal (11553292) 13 October 2021 (has links)
<p>Entomophagy, which is the habit of eating insects, has become relevant in the past few years as it could potentially help reduce current and future food insecurity, due to the highly nutritious and sustainable characteristics of edible insects. In addition to the nutritional content of insects, research on the potential bioactive components of insect extracts has also gained popularity. In this study, extracts from house cricket (<i>Acheta domesticus</i>) from two farms and their corresponding feeds were obtained using a microwave-assisted extraction. Further phenolic characterization led to the identification and quantification of 4-hydroxybenzoic acid, <i>p</i>-coumaric acid, ferulic acid and syringic acid as major phenolic compounds in both <i>A. domesticus </i>extracts as well as both feed extracts. Additionally, <i>in vitro</i> antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl radical cation (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical assays. In both <i>in vitro</i> assays, <i>A. domesticus</i> extracts showed higher antioxidant activity compared to the feeds. Antibacterial activity against <i>E. coli</i> and <i>L. innocua</i> was also evaluated using the microwell method. The <i>A. domesticus </i>extracts showed a selective inhibition (p<0.05) towards the gram-positive bacteria <i>L. innocua </i>between a period of 4 to 8 h. This inhibition is thought to have occurred as a result of the presence of phenolic acids and antimicrobial peptides, while the feed extracts did not exhibit any inhibitory activity towards any of the bacteria. The finding of the same phenolic acids in <i>A. domesticus</i> and their corresponding feed could imply the capacity of <i>A. domesticus</i> to absorb and sequester dietary phenolics that may provide additional health benefits when the insect is consumed, unveiling new benefits of entomophagy. </p>
7

Comparison of Functional, Nutritional, and Sensory Properties of Spray-Dried and Oven-Dried Cricket (<em>Acheta domesticus</em>) Powder

Bassett, Fred Stephen 01 April 2018 (has links)
Three dried cricket products – Oven-roasted Cricket Meal (ORCM), Oven-roasted Cricket Powder (ORCP), and Spray-dried Cricket Powder (SDCP) – were prepared and compared to assess their relative nutritional, functional, and sensory properties. The range of particle sizes in SDCP was wider than that of ORCP; while SDCP had more particles in the 7.78-22.0 µm range, it also had more particles in the 176-498 µm range, which contributed to differences in functional and sensory properties. ORCM and SDCP meet the FDA definition of an "excellent source" of vitamin B2, ORCP is a "good source" of vitamin B2, and all three products are an "excellent source" of vitamin B12 and vitamin E at a serving size of 100 g. The addition of ORCP to a protein drink at 30% did not significantly affect its sensory acceptance, while the drink prepared with SDCP was rated significantly worse in every attribute, and the drink prepared with ORCM had varied effects on the different sensory attributes.
8

Modifying the Mineral Profile of Crickets (<i>Acheta Domesticus</i>) Using a Supplemented Diet

Maxwell, Rhianne Morgan Le 01 August 2018 (has links) (PDF)
Captive insectivores may consume invertebrates as all, or part of their overall diet. The challenge with feeding captive insectivores involves the limited number of invertebrate species that are commercially available, and the lack of key nutrients provided by these insects. Among these insects, a naturally occurring low concentration of calcium and an inverse calcium to phosphorus ratio may put insectivores at the risk of developing hypocalcemia. A strategy to correct this nutrient imbalance involves supplementing the insect diet with high concentrations of targeted nutrients – a term referred to as gut-loading. Current industry guidelines recommend feeding a supplemented diet for 48 to 72 h before offering the insect to an insectivore. In the present study, the mineral profile of adult crickets (Acheta domesticus) offered a maintenance diet (1.58% Ca, DMB) are compared to crickets offered a supplemented diet (11.32% Ca, DMB) over 120 h. The supplemented diet produced a cricket with significantly higher calcium concentration compared to the maintenance diet. The calcium concentration of crickets offered the supplemented diet was highest at 48 h (0.63%), but did not achieve a 1:1 Ca:P ratio nor meet the lowest reported nutrient requirements of carnivorous reptiles, omnivorous reptiles, or an insectivorous bird at various life stages. Although the supplemented diet improved the whole body calcium concentration in feeder crickets, the crickets do not provide adequate calcium, iron, or manganese to meet the requirement of insectivores. As evidenced by the current study, the supplemented crickets are not recommended to serve as the sole source of nutrition for an insectivore.
9

CAN NUTRITIONAL GEOMETRY MODULATE THE EFFECTS OF DIETARY RESTRICTION IN ACHETA DOMESTICUS?

LeBlanc, Zillon K. 10 1900 (has links)
<p>This study was performed to better understand the physiological responses of the cricket <em>Acheta domesticus</em> to dietary restriction and nutritional geometry (relative nutritional balance). Dietary restriction in crickets decreases the growth rate, survivorship, maturation mass and delays maturation, but it has the benefit of increasing their maximum longevity. Measurements of maturation mass, maturation age and longevity were obtained and used to calculate adult duration, growth rate and survivorship. This experiment combined both dietary restriction and nutritional geometry. Treatments were dietary restricted and provided with one of three macronutrients: lipid, carbohydrate or protein. The macronutrients were predicted to modulate the effects of dietary restriction while still producing an increase in maximum longevity. The lifetime restricted males and females obtained the highest maximum longevity of all treatments. The females of the carbohydrate treatment experienced significant increases in survivorship when compared to the lifetime restricted treatment. The males of the carbohydrate treatment achieved the second highest maximum longevity as well as a significant increase in longevity when compared to the lipid and protein males. A significantly earlier maturation age was obtained by the carbohydrate males when compared to the lifetime restricted treatment. The protein females had a significantly higher maximum longevity than the control treatment. The lipid treatment had an extremely low survivorship, a decreased adult duration as well as a low maturation mass. In summary, carbohydrates decreased the maturation age and increased the survivorship of the female crickets and increased the longevity of the male crickets. The protein treatment did not obtain the expected increases in growth rates or maturation mass associated with high protein diets. Therefore, different high protein diets should be tested in conjunction with the carbohydrate diet, in order to offset the negative effects of dietary restriction.</p> / Master of Science (MSc)
10

Purification and Characterization of Acheta domesticus and Gryllodes sigillatus Cricket Chitin and Chitosan for Bioactive and Biodegradable Food Packaging Applications

Morgan J Malm (11763944) 03 December 2021 (has links)
<p>The production of insects for protein is projected to reach a market share of 1.33 billion USD, a rapid increase from the estimated 144 million USD share of 2019 market. The isolation of insect protein produces by-products, including chitin. Currently chitin is extracted from aquaculture by-products, such as shrimp and crab shells, and used to produce chitosan for various applications in the supplement and food industry. With the insect market expected to continue its growth, the feasibility of sourcing commercial chitin and chitosan from reared crickets’, and the application properties of its counterpart, chitosan, was investigated in this dissertation. In the first part of this dissertation, chitin from two commonly reared crickets in the Unites States, <i>Acheta domesticus</i> and <i>Gryllodes sigillatus</i>, was successfully extracted, purified, and identified as a commercially viable option for chitin and chitosan. Extensive crustacean chitin studies served as the foundation of purification steps, however durations were adjusted to account for intrinsic differences between insects and crustacean exoskeletons. Furthermore, cricket chitosan was prepared and optimized with varying degrees of deacetylation. As expected, cricket chitosan had lower molecular but did not have a detectable effect on the bioactive properties tested. All cricket chitosan produced had similar lipid binding capacity <i>in vitro</i>. Additionally, the microbial inhibition of cricket chitosan and commercial chitosan (~70% DDA) were not significantly different when evaluated against <i>L. innocua</i> and <i>E. coli</i>. High DDA cricket chitosan showed greatest bacterial inhibition as expected. In the second part of this dissertation, cricket derived chitosan showed similar and improved food packaging properties, when evaluated against commercial shrimp chitosan. microstructure analysis provided by scanning electron microscopy showed greater compaction and agglomeration of cricket chitosan films. The change in microstructure may be attributed to the increased complexity generally attributed to insect chitosan materials, a result of remaining melanin and protein in close association with insect exoskeleton chitosan. As a result, cricket films had similar or increased tensile strengths but decreased elongation percentages when compared to shrimp films. Water vapor permeability of cricket films was decreased due to tortuosity. Residual melanin likely played an important role in increasing cricket film surface hydrophobicity and providing enhanced light barrier properties. Overall, this dissertation successfully shows the potential of crickets as insect derived chitin and chitosan, and its effectiveness as a lipid binding and antibacterial agent, as well as its potential use in biobased food packaging. </p>

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