Anna Adámková

Nutritional Potential of Selected Insect Species Reared on the Island of Sumatra

Inhabitants of the Indonesian island of Sumatra are faced with the problem of insufficient food supplies and the consequent risk of undernourishment and health issues. Edible insects as a traditional and readily available food source could be part of the solution. The nutritional value of insects depends on many factors, e.g., species, developmental stage, sex, diet, and climatic conditions. However, edible insects bred in Sumatra for human consumption have never before been assessed with regard to their nutritional value. Our study involved analyses of crude protein, chitin, fat and selected fatty acid contents of giant mealworm larvae (Zophobas morio), larvae of the common mealworm (Tenebrio molitor) and nymphs of the field cricket (Gryllus assimilis). Crude protein content in the samples ranged from 46% to 56%. Highest (35%) and lowest (31%) amounts of fat were recorded in giant mealworm larvae and larvae of the common mealworm, respectively. Chitin amounts ranged from 6% to 13%. Based on these values, which are comparable to those known from other food insects reared in different regions of the world, the edible species bred in Sumatra could become food sources with a potential to help stave off hunger and undernourishment.

The effect of drying on antioxidant activity of selected lamiaceae herbs

Antioxidant activity and total phenolics content of selected fresh and dried herbs from the Lamiaceae family were compared. The analysed herbs included Thymus vulgaris , Origanum vulgare , Satureja hortensis , Origanum majorana , and Origanum heracleoticum from the 1 st and the 2 nd harvests. The antioxidant activity was determined using DPPH method and the total content of phenols was analysed using the Folin-Ciocalteu reagent. Ascorbic and gallic acids were used as reference standards. All the analysed herbs had the reasonable potential to reduce the DPPH radical. The dried herbs from the 2 nd harvest had the highest antioxidant activity. Oregano exhibited the highest antioxidant activity from the analyzed samples of both harvests together. The descending order of the samples was oregano ˃ Greek oregano ˃ marjoram ˃ summer savory ˃ thyme. Marjoram from the 2 nd harvest had the highest antioxidant activity from the fresh samples. The lowest activity was observed in thyme from the 2 nd harvest. In case of dried samples, the highest antioxidant activity was measured in sample of Greek oregano from the 2 nd harwest. The lowest activity was observed in thyme from the 1 st and 2 nd harvest again. The descending order of total phenolics content for both harvests together was oregano ˃ Greek oregano ˃ marjoram ˃ summer savory ˃ thyme. In case of fresh herbs the highest total phenolics content was measured in oregano from the 1 st harvest, the lowest content was measured in summer savory from the 2 nd harvest. Greek oregano from the 2 nd harvest had the highest values from dried herbs. Dried thyme from the second harvest had the lowest total phenolics content. The correlation between the DPPH values and the total content of phenols was determined (for fresh herbs: 0.4917; for dried herbs: 0.8698). According to the total content of phenols a statistically significant difference between the fresh and dried herbs from the 2 nd harvest ( p = 0.0185) was found.

Effect of sex on the nutritional value of house cricket, Acheta domestica L.

Since January 2018, insects have been recognised as novel foods in the EU, but their nutritional value varies, and factors affecting their nutritional composition have been debated. We investigated the effect of sex on the nutritional value and chemical composition of the house cricket (Acheta domestica L.). Both sexes were rich in protein and lipids. The proximate composition was partly influenced by sex; females contained a significantly higher amount of lipids (18.3-21.7 vs 12.9-16.1 g/100 g dry matter, p = 0.0001) and fewer proteins than males (61.2-64.9 vs 66.3-69.6 g/100 g dry matter, p = 0.0001). Males contained more chitin (p = 0.0015) and nitrogen chains (p = 0.0003) than females. Only the ash (p = 0.4314) and nitrogen-free extract (p = 0.4871) were uninfluenced by sex. Furthermore, nutrient quality expressed as essential amino acid (72.3-77.1), thrombogenicity (1.22-1.45), and atherogenicity indices (0.53-0.58) did not differ between sexes (p > 0.05).

Effect of different storage conditions on the microbiological characteristics of insect

When introducing a novelty food, its safety needs to be monitored. One of the safety aspects of human health is microbial contamination. In this work, microbiological parameters of long-term stored edible insect material - mealworm ( Tenebrio molitor ), lesser mealworm ( Alphitobius diaperinus ), field cricket ( Gryllus assimilis ), and migratory locust ( Locusta migratoria ) were evaluated. The monitored indicators (colony forming units, enterobacteria, lactic acid bacteria, yeasts and moulds) were evaluated using common microbiological methods. All samples of stored insect were determined as safe for human consumption, except for the lesser mealworm sample from 2016, in which case the limit was exceeded. Sample of adult field cricket seems to be suitable for long-term storage, as it contained the lowest amount of microorganism. Sample of dried Gryllus assimilis from 2014 had the lowest microbial contamination. Further results suggest that, for long-term storage, the most suitable way of preparation is killing with boiling water, drying at 103 °C for 12 hours and subsequent hermetic packaging.

Comparison of the content of selected mineral substances in Czech liturgical and common wines

The article deals with the content of selected mineral substances in Czech liturgical wines and compares them with common wines. Sulphur, phosphorus, boron, potassium, calcium, magnesium, iron, cadmium and lead were selected as evaluated minerals, and they were all found in all the analyzed varieties - Pinot Noir, Red Traminer and Chardonnay. Mineral substances were determined using a quadrupole mass spectrometer in the inductively coupled plasma variant of the Thermo Scientific ICAP Q ICP-MS. Generally, measured results did not show significant differences between the mineral content in liturgical and common wines. Therefore the influence of specific production technologies of liturgical wines on the mineral contents was not proved either. One of the highest mineral concentration was in communion Red Traminer, which, besides beneficial minerals, also contained a high amount of toxic elements. On the contrary, common Red Traminer had one of the lowest concentrations of toxic compounds. The content of permitted lead levels was exceeded in a single case, namely in the Chardonnay kosher sample. For cadmium, no sample exceeded the allowed limit.

Acceptability and sensory evaluation of energy bars and protein bars enriched with edible insect

For consumers, one of the basic criteria of choosing a foodstuff, apart from nutritional values, is their taste and smell. In edible insect as a novel food, these criteria are not quite decisive. The main criterion in the Western countries is the acceptability of the food. This work deals with sensory evaluation of protein and energy bars, enriched with cricket flour from American and Czech producers, and their acceptability for consumers from the Czech Republic. The sensory evaluation was done using the questionnaire survey and a simple electronic nose. The survey has shown that edible insect bars are acceptable as a new type of food for consumers in the Czech Republic. Best rated by consumers were orange and pineapple flavour bars from the Czech manufacturer. Statistically significant difference was not detected between evaluation of the bars from the American and Czech manufacturers. Also, the difference between the bars of different flavours from the Czech producer was evaluated using a simple machine - a portable electronic nose. There was not a statistically significant difference between bars of different flavours from the American manufacturer. The positive contribution of the survey is that more than 80% of consumers are willing to consume food enriched with edible insect. This fact shows a change in public attitude to these foods.

The importance of higher alcohols and esters for sensory evaluation of rheinriesling and chardonnay wine varieties

For a consumer, one of the first characters for evaluation of wine is its scent. A pleasant aroma of wine associated with the subsequent taste experience can be remembered by the consumer for a long time and appreciated appropriately. For this reason, the aromatic properties of wine are very important to both consumers and producers. The question, however, is to assess the evaluation of wine sensory evaluation based on a rapidly developing chemical analysis without the use of a panel of evaluators. This study has dealt with the problem of the correlation of sensory evaluation of wine with the total content of higher alcohols and esters in wine prepared from the same wine varieties (Rheinriesling and Chardonnay) on the same vineyard under the same climatic conditions and processed using the same production technology in the years 2008 - 2012. The total content of higher alcohols and esters was determined by gas chromatography with a mass spectrometer (GC/MS). The correlation between the sensory evaluation and the total content of higher alcohols has not been established. However, the direct effect of the total content of the esters on the level of the sensory analysis of the two varieties studied was demonstrated. This can be an important economic indicator for a manufacturer who can estimate the sensory quality of the wine only on the basis of chemical analysis and thus estimate the success of the wine on the consumer market. Normal 0 21 false false false EN-GB X-NONE X-NONE

Electronic nose in edible insects area

Edible insect is appraised by many cultures as delicious and nutritionally beneficial food. In western countries this commodity is not fully appreciated, and the worries about edible insect food safety prevail. Electronic noses can become a simple and cheap way of securing the health safety of food, and they can also become a tool for evaluating the quality of certain commodities. This research is a pilot project of using an electronic nose in edible insect culinary treatment, and this manuscript describes the phases of edible insect culinary treatment and methods of distinguishing mealworm ( Tenebrio molitor ) and giant mealworm ( Zophobas morio ) using simple electronic nose. These species were measured in the live stage, after killing with boiling water, after drying and after inserting into the chocolate.The sensing device was based on the Arduino Mega platform with the ability to store the recorded data on the SD memory card, and with the possibility to communicate via internet. Data analysis shows that even a simple, cheap and portable electronic nose can distinguish between the different steps of culinary treatment (native samples, dried samples, samples enriched with chocolate for cooking) and selected species. Another benefit of the electronic nose could be its future introduction into the control mechanisms of food security systems (e.g. HACCP).

Detection of selected heavy metals and micronutrients in edible insect and their dependency on the feed using XRF spectrometry

Edible insect can be a valuable source of nutrients, but also a potential source of heavy metals. Quick detection of over-limit heavy metals concentration could be a key to processing and quick distribution of edible insect products. The aim of this work was to evaluate the feed-dependent content of heavy metals in the mealworm and superworm using the X-ray fluorescence spectrometry as an easy, cheap and a timeless screening method for evaluating the content of heavy metals and microelements. Using a handheld analyser the content of Cd, Pb, Cu and Zn were detected. Both analysed species proved dependency of metal content on a feed. Detected level of Cu in mealworm was between 571 mg.kg -1 and 1768 mg.kg -1 and in superworm from 571 mg.kg -1 to 1768 mg.kg -1 based on the feed. The content of Zn was similar, between 725 mg.kg -1 and 1437 mg.kg -1 in mealworm and 555-1482 mg.kg -1 in superworm. The level of Pb was below the detection limit in all samples, thus from this point of view this food seems to be safe. On the contrary, the content of Cd in the dry matter samples was above the food limit - 147 mg.kg -1 to 230 mg.kg -1 . From this point of view, the samples were evaluated as unsuitable for consuming.

The estimated possibilities of process monitoring in milk production by the simple thermodynamic sensors

The characterization and monitoring of thermal processes in thermodynamic systems can be performed using the thermodynamic sensors (TDS). The basic idea of thermodynamic sensor is possible to use in many various applications (eq. monitoring of frictional heat, thermal radiation, pollution of cleaning fluid, etc.). One of application areas, where the thermodynamic sensor can find the new area for a using, is a production of milk products - cheese, yogurt, kefir, etc. This paper describes the estimated possibilities, advantages and disadvantages of the use of thermodynamic sensors in diary productions and simple experiments for characterization and monitoring of basic operations in milk production process by thermodynamic sensors. The milk products are often realized by fermenting or renneting process. Final stages of fermentation and renneting processes are often determined on the base of sensory evaluation, pH measurement or by analytical method. The exact time of the fermentation process completion is dependent on various parameters and is often the company know-how. The fast, clean and simple non-analytical non-contact method for monitoring and for the determination of process final stages does not exist in this time. Tests of fermentation process, renneting process and yoghurt process by thermodynamic sensors were characterized and measured in this work. Measurement of activity yeasts was tested in first series of experiments. In second series of experiments, measurement of processes in milk production was tested. First results of simple experiments show that the thermodynamic sensors might be used for determination of time behaviour of these processes. Therefore, the milk products (cheese, yogurt, kefir, etc.) is opened as a one of new application areas, where the thermodynamic sensor can be used.