The dielectric properties of six refined edible oils with different fatty-acid compositions were determined for oils incubated at 180 °C up to 40 h. The oil degradation was evaluated by the ...dielectric dispersion and dielectric loss in the frequency range from 40 Hz to 2 MHz at 25 °C, refractive index, density, saponification number, and specific absorption coefficient at 232 and 268 nm. The dependence of the dielectric properties on frequency has been evaluated with Corach, Cole–Cole, and the universal power law models, giving the novel strategies for the interpretation of the dielectric spectra of thermally treated oils. The derived parameters—the dielectric constant, the electrical conductivity, the relaxation time τ and the exponents α, p, and n—are discussed with respect to the increased oxidation evidenced by specific absorption coefficients and polar products, as measured by the dielectric constant of the thermally treated oils. The specific refraction, specific polarization, orientation polarization, and dipole moment were determined using Lorenz–Lorentz, Debye and Onsager relationship. All above parameters obtained increased during the thermal treatment, except specific refraction, the electrical conductivity and the relaxation time. The dielectric constant-macroscopic parameter was compared with microscopic parameter polarization and dipole moment; the linear dependence was found to be R 2 = 0.971 .
The COVID-19 pandemic caused a large and involuntary shift to work from home (WFH) or teleworking, and widespread adoption of web-based platforms. This study aims to uncover the attitude and ...perception of WFH and online education among students and employees of the University of Ljubljana. A web-based questionnaire survey was conducted in November 2020, and more than 1300 valid responses were received. The lack of daily commuting, improved eating habits, and more time available for a family were the main reported advantages of WFH. The main issues, highlighted by respondents, were higher stress levels, lower study/work efficiency, and poorer working environment at home. When comparing the online educational process with the traditional one, the absence of traditional laboratory work, inadequate social interactions, and limitations of online knowledge assessment were identified as drawbacks by both students and educators. A significant difference between students and educators was observed in their opinion on the efficiency of online lectures compared to traditional ones, with the former being significantly more favored by students than educators. Overall, the majority of the respondents from all groups wish for the pre-COVID-19 study/work mode to be established as soon as possible. This implies that the perceived drawbacks of online education outweigh its advantages.
The aim of this study was to determine the influence of joining university on dietary habits, intake of food, and physical activity of students at the Biotechnical Faculty of the University of ...Ljubljana. Overall, 226 students (82.3% female) self-evaluated their dietary habits and their physical activity before and after starting university. A change in dietary habits was evident for the majority of the students (female: 74.7%; male: 67.5%). After starting their studies, ~20% of students consumed less fruits and vegetables, and only 28.8% and 15.5% of the students consumed fresh fruit and fresh vegetables, respectively, more than once a day. Female students were more likely to prepare home-cooked meals (almost 50%; at least 4 times a week), while male students were more likely to eat in restaurants with subsidised meals. Approximately 70% of the students reported negative changes in their motor skills after starting university and of these, 90% also reported negative change in their dietary habits, as evidenced by higher consumption of savoury snacks and lower consumption of fresh vegetables. Since our results show a negative influence of joining university on dietary habits and physical activity, more attention needs to be paid to the critical factors involved.
Fatty acid composition of different cultivars of blackcurrant (Ribes nigrum L.), redcurrant (Ribes rubrum L.), gooseberry (Ribes uva-crispa L.) and jostaberry (Ribes nidrigolaria Bauer) was studied. ...These seeds contained from 17.8% to 22.4% of oil. The major fatty acid (FA) determined in these Ribes species was linoleic acid and significant differences were determined between the seeds of these Ribes species for all fatty acids analysed, except for stearic acid. Jostaberries had the lowest n-6/n-3 ratio, Index of Atherogenicity, Index of Thrombogenicity and the highest α-linolenic and stearidonic acid contents. Blackcurrants had the highest γ-linolenic acid content, followed by gooseberries. With their favourable FA composition, seeds of these Ribes species represent an interesting new source of essential FA that can be used as a supplement in everyday nutrition.
•Seed oil content and fatty acids were analysed across Ribes species and cultivars.•Seeds showed similar oil contents across species, but varied fatty acid compositions.•The main fatty acids in these seeds were linoleic, α-linolenic and γ-linolenic.•γ-Linolenic acid prevails in blackcurrant, stearidonic acid prevails in jostaberry.•Good nutritional quality of these Ribes seeds supports their use as food supplements.
The success of new food processing technologies is highly dependent on consumers’ acceptance. The purpose of this paper is to study consumers’ perceptions of two new processing technologies and food ...products produced by means of these novel technologies. To accomplish this, a qualitative study on consumer attitudes towards high-pressure processing (HPP) and pulsed electric field (PEF) processing of food was carried out. In all 97 adults between 20 and 71 years of age participated in 12 focus groups conducted in Slovenia, Hungary, Serbia, Slovakia, Norway and Denmark using a common guideline. Participants were introduced to the HPP and PEF technologies and then to the effect of the two new technologies on two specific product categories: juice and baby food. The transcribed data was content analysed and the coded data was transformed into diagrams using UCINET 5 and NETDRAW. The results show that consumers perceived the main advantages of HPP and PEF products to be the products’ naturalness, improved taste and their high nutritional value, whereas the main disadvantage was the lack of information about the PEF and HPP products. The results of the participants’ evaluation of the PEF and HPP processes showed that environmental friendliness and the more natural products were seen as the main advantages, while they were concerned about body and health, the higher price of the products, the lack of information about the technologies and a general scepticism. The study also shows that North European participants were a bit more sceptical towards PEF and HPP products than the East European participants.
Zdrav način prehranjevanja je v obdobju mladostništva, zaradi intenzivne rasti in številnih fizioloških sprememb, izjemno pomemben. Obroki v dijaških domovih morajo biti načrtovani skladno s ...Smernicami za prehranjevanje v vzgojno-izobraževalnih zavodih (Smernice). Cilj raziskave je bil ovrednotiti energijsko in hranilno vrednost kosil in večerij v dijaškem domu v Ljubljani ter oceniti njihovo skladnost s Smernicami. Posamezne jedi v ponujenih obrokih smo stehtali ter s spletnim orodjem Odprta platforma za klinično prehrano ovrednotili vsebnost energije in makrohranil. Dijaki so z 9-točkovno hedonsko lestvico ocenjevali senzorično sprejemljivost obrokov. Rezultati so pokazali, da so bile povprečne energijske vrednosti kosil skladne s priporočili za energijski vnos za dekleta, za fante pa so bile premajhne. Povprečna energijska vrednost večerij je bila v vseh treh tednih večja od priporočene za dekleta, medtem ko je bila za fante premajhna v 1. tednu in skladna v drugih dveh tednih. Povprečni vnosi energije z beljakovinami s kosili so bili preveliki, v nasprotju pa so bili povprečni vnosi energije z ogljikovimi hidrati s kosili in večerjami premajhni v vseh treh tednih. Dijaki so v povprečju preveč energije zaužili z maščobami. Povprečna hedonska ocena kosil na 9-točkovni hedonski lestvici je bila 6,5 ± 1,9, povprečna hedonska ocena večerij pa 6,6 ± 1,9.
This study investigated nutritional value, oxidative status and sensory properties of 14 unconventional oils and fats, from flaxseed, sacha inchi, hemp seed, rapeseed, mustard seed, walnut, argan, ...grape seed, black cumin, camelina, peanut, poppy seed, coconut and ghee butter. Their fatty acid composition and peroxide values were determined, and their sensory profiles were evaluated by an expert panel. Data demonstrated unfavourable n-6/n-3 fatty acid ratios for grape seed, black cumin, peanut and poppy seed oils, which were otherwise rich in linoleic acid. Hemp seed, rapeseed, mustard seed and walnut oils had the most favourable n-6/n-3 fatty acid ratios. Oils with fatty acid composition close to that recommended were rapeseed oil, mustard seed oil (without erucic acid) and camelina oil. Erucic acid, which may be potentially harmful to health at high levels of chronic exposure, was detected in rapeseed, mustard seed and camelina oil. The oils and fats differed in intensities of their sweet taste and various descriptors of aroma. Sensory analysis rendered certain samples as unsuitable for human consumption due to the presence of fusty odour and aroma. In the majority of samples, lipid peroxide levels exceeded the maximum permitted levels and should be excluded from the market.
Proper nutrition is an essential part of an individual’s defence against numerous diseases including coronavirus disease SARS-CoV-2 (Covid-19). Nutritional status of individual is affected by several ...factors such as age, sex, health status, physical activity, life style and medications. Optimal nutrition and dietary nutrient intake impact the immune system, therefore the sustainable way to survive in current context is to strengthen the immune system. Inadequate intake of energy, protein, and specific micronutrients are associated with depressed immune function and increased susceptibility to infection. Predominantly vital for the encouraging of immune function are elements selenium, iron and zinc and vitamins A, D, C, E, B6, B9 (folate) and B12 as well as omega-3 polyunsaturated fatty acids. Thus, during this time it is important to take care of nutritional habits, following a healthy and balanced nutritional pattern containing a high amount of elements, antioxidants and vitamins. It is also recommended, that individuals should be mindful of physical activity, known to be associated with all-cause mortality. Regular physical activity also improves mental health and overall feelings of wellbeing. Thus, now in the time of epidemic, more than ever, wider access to healthy foods should be a top priority for governments around the world
Black currant is known as a fruit with a very strong in vitro antioxidative capacity, but its in vivo antioxidant efficacy has not yet been characterized. The aim of the experiment was to determine ...the potency of black currant juice in comparison to vitamin E, for decreasing oxidative stress. Oxidative stress was induced by high intake of polyunsaturated fatty acids (PUFAs) in pigs as a model for humans. Twenty-four growing pigs were divided into four groups. All groups received isocaloric daily rations composed of an equal amount of basal diet that was supplemented with starch (CONT), linseed oil (OIL), linseed oil and black currant juice (OIL+BCJ), or linseed oil and vitamin E (OIL+VIT E). The experiment confirmed that the high proportion of PUFAs in the OIL group increased oxidative stress. In comparison with the OIL group, vitamin E supplementation significantly lowered plasma malondiadehyde (MDA) and the 24-hour urine MDA excretion rate, and reduced the degree of DNA damage in leukocytes to the level of the CONT group. The black currant juice intake failed to significantly decrease plasma MDA and 24-hour urine MDA excretion rate, but did reduce the degree of DNA damage in leukocytes to the level of the CONT group, as well as increase plasma β+γ-tocopherol concentrations. Although black currant juice did not reduce the formation of MDA, it efficiently prevented DNA damage induced by the high intake of PUFAs. It could be concluded that under these experimental conditions vitamin E was more efficient as an antioxidant that black currant juice.
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