Activity concentrations and distribution of radionuclides in surface and core sediments of the Neretva Channel (Adriatic Sea, Croatia)

The activity concentrations and the distribution of manmade 137Cs and naturally occurring radionuclides 40K, 238U and 232Th in surface and core sediments of the semi enclosed, river-dominated marine environment of the Neretva Channel were investigated in relation to the sedimentological characteristics and the content of the total organic carbon (TOC). The activity concentrations of radionuclides were determined by gamma spectrometry. Distinct interrelations between sediment properties and spatial distribution of radionuclides were established. The highest accumulation of 137Cs was found close to the river mouth, in the region of intensive deposition of organic matter of terrestrial origin. This finding implies that the river-borne organic material and its deposition processes should be considered as the most important factor controlling distribution of 137Cs in this transitional land-sea environment. The sediment accumulation rates, estimated from distribution of 137Cs in core sediments, were approximately 6 mm y-1 in front of the Neretva River mouth and 4 mm y-1 in the channel area. The spatial distribution of natural 40K and 232Th radionuclides indicates their distinct association with fine-grained sediments. The interrelation of 238U with fine-grained particles was somewhat weaker but still present. The results obtained indicate that the accumulation pattern of natural radionuclides in the Neretva Channel sediments is mainly governed by the deposition of fine-grained material. This study scrutinizes the baseline level for occurring radionuclides and should be used for monitoring and assessing the radionuclide pollution record in the investigated transitional land-sea environment of the Adriatic

NEAR INFRARED SPECTROSCOPY (NIRS) AS FOOD QUALITY AND FOOD FRAUD DETECTOR – APPLIED ON FISH STICKS

The aim of this study was to present the professional application of near infrared spectroscopy (NIRs) in the detection of food quality on purchased fish sticks. The measured NIR spectra of samples prepared from fish or squid were related to nutritional labels such as the amount of certain macronutrient and the proportion of the starting material (fish/squid). In the standard procedure, NIRs coupled with chemometric tools such as principal component analysis (PCA) and partial least square regression (PLSR) was used to investigate the qualitative and/or quantitative capabilities in determining food quality. Excellent qualitative differentiation was achieved with PCA, with biplots showing how the explanation of variation increased from 80.12 % when only nutritional information was used in the observation to 96.89% when nutritional information was coupled with the corresponding NIR spectrum. Since higher levels of animal protein in food are associated with an increase in price, the detection probabilities of different protein sources (fish/meat) were tested using PLSR, with 100% of the samples successfully detected. PLSR was also used to detect the correlation of the NIR spectra to the macronutrient contents and the strongest correlation was determined for proteins (R2 = 0.99). The results confirmed the feasibility of using NIRs in the qualitative evaluation of samples where it is possible to determine the predominance of fish or squid, and also to estimate the expected protein content. The protein content is related to the price of the product, since all products containing animal proteins have higher prices that grow proportionally to their share. NIRs is not a qualitative method, but it can help in the selection of products, whose exact composition and possible adulteration can be confirmed by additional laboratory analysis

NEAR INFRARED SPECTROSCOPY (NIRS) AS FOOD QUALITY AND FOOD FRAUD DETECTOR – APPLIED ON FISH STICKS

The aim of this study was to present the professional application of near infrared spectroscopy (NIRs) in the detection of food quality on purchased fish sticks. The measured NIR spectra of samples prepared from fish or squid were related to nutritional labels such as the amount of certain macronutrient and the proportion of the starting material (fish/squid). In the standard procedure, NIRs coupled with chemometric tools such as principal component analysis (PCA) and partial least square regression (PLSR) was used to investigate the qualitative and/or quantitative capabilities in determining food quality. Excellent qualitative differentiation was achieved with PCA, with biplots showing how the explanation of variation increased from 80.12 % when only nutritional information was used in the observation to 96.89% when nutritional information was coupled with the corresponding NIR spectrum. Since higher levels of animal protein in food are associated with an increase in price, the detection probabilities of different protein sources (fish/meat) were tested using PLSR, with 100% of the samples successfully detected. PLSR was also used to detect the correlation of the NIR spectra to the macronutrient contents and the strongest correlation was determined for proteins (R2 = 0.99). The results confirmed the feasibility of using NIRs in the qualitative evaluation of samples where it is possible to determine the predominance of fish or squid, and also to estimate the expected protein content. The protein content is related to the price of the product, since all products containing animal proteins have higher prices that grow proportionally to their share. NIRs is not a qualitative method, but it can help in the selection of products, whose exact composition and possible adulteration can be confirmed by additional laboratory analysis

Application of NIR spectroscopy in gluten detection as a cross-contaminant in food

The determination of gluten is of critical importance when food screening is intended for special groups such as food ingredient intolerant and allergic persons. Cross-contamination of food that does not contain gluten is also possible in the sales chain. The aim of this study was to determine the applicability of Near-Infrared Spectroscopy (NIRs) for the detection of gluten traces in rice, rice flour, corn flour and corn grits. In the cross-contamination simulation, two types of wheat flour were used. They were added to rice, rice flour, corn flour and corn grits in a range from 5 % to 30 %. Apart from the spectra of pure and contaminated samples, conductivity and total dissolved solids were monitored to determine changes in the samples. NIR spectroscopy was combined with chemometric techniques to determine at which wavelengths a glutenfree fingerprint can be detected. Although experiments were carried out with a NIR instrument that monitors molecular vibrations in the range of λ= 904-1699 nm, the gluten fingerprint was successfully determined, regardless of the type of flour that was added to the rice, rice flour, corn flour and corn grits. All concentrations of the added flours were successfully determined and models were developed to detect the concentrations of the added flours. Even the conductivity showed good prediction potential in gluten determination. Regardless if the investigated samples were contaminated or not, the determination coefficient R2 was over 0.9. Developed models could be used to predict possible wheat flour contamination of any rice or corn product samples or samples prepared for cooking in water

OPTIMIZATION OF ETHANOL/WATER SOLVENT EXTRACTION OF BIOACTIVE COMPONENTS ORIGINATING FROM INDUSTRIAL HEMP (Cannabis sativa L.)

Hemp (Cannabis sativa L.) contains a wide range of biocompounds with different beneficial properties such as anti-inflammatory, antithrombotic, antiarrhythmic, hypolipidemic and antioxidative. Response Surface Methodology (RSM) coupled with Box-Behnken design (BBD) was applied to determine the influence of extraction temperature, liquid to solid ratio, extraction time, rotational speed and ethanol/water solvent ratios at three levels on the solid-liquid extraction of the bioactives from the hemp (flowers, leaves, seeds, stems). Based on the obtained results, liquid to solid ratio, temperature and ethanol/water solvent ratio had statistically significant effects on the total polyphenolic content (TPC), while extraction time and rotational speed had no influence on the TPC extraction. Regarding antioxidant activity (AOX) determined by the DPPH method, only liquid to solid ratio had a statistically significant effect. Liquid to solid ratio, ethanol/water solvent ratio, temperature and rotational speed significantly influenced AOX determined by the FRAP method. According to BBD, the optimum extraction conditions were as follows: extraction temperature 45 °C, liquid to solid ratio 30 mL/g, extraction time 25 min, rotational speed 500 rpm, ethanol/water solvent ratio 25%. RSM coupled with a BBD model was shown to be effective for optimization the solid-liquid extraction of hemp

NEAR INFRARED SPECTROSCOPY (NIRS) COUPLED WITH CHEMOMETRIC TOOLS USED FOR FOOD PRODUCTS ADULTERATION DETECTION

The growing problem of food products adulteration requires a rapid and simple method for adulteration detection. Adulterants, which can range from plant material to natural and synthetic colours and compounds have a severe influence on customer trust as well as public health risks. Food safety regulations are being tightened and expanded, requiring a more thorough examination of hazards and risk management solutions. Due to its advantages, near infrared spectroscopy has been recognised as an effective method for food adulteration detection. In this work, an overview of the basics of NIR spectroscopy, NIR data analysis and the use of NIR for food adulteration detection are discussed

NEAR INFRARED SPECTROSCOPY (NIRS) COUPLED WITH CHEMOMETRIC TOOLS USED FOR FOOD PRODUCTS ADULTERATION DETECTION

The growing problem of food products adulteration requires a rapid and simple method for adulteration detection. Adulterants, which can range from plant material to natural and synthetic colours and compounds have a severe influence on customer trust as well as public health risks. Food safety regulations are being tightened and expanded, requiring a more thorough examination of hazards and risk management solutions. Due to its advantages, near infrared spectroscopy has been recognised as an effective method for food adulteration detection. In this work, an overview of the basics of NIR spectroscopy, NIR data analysis and the use of NIR for food adulteration detection are discussed

Emulgiranje na mikrorazini: brže, bolje i učinkovitije

Emulsions are traditionally prepared with the application of high shear forces generated by the use of static mixers, homogenisers, or ultrasound. The resulting emulsions are sensitive to change of process conditions. The application of high forces and temperatures can significantly affect the constituents of the emulsions and their final stability. Microfluidic technology seems to be a very efficient alternative to classic emulsification methods. The dimensions of microdevices in combination with continuous processes offer a great advantage over classic batch emulsification processes carried out on a larger scale. The small dimensions of the microdevices allow easy transport of equipment, better control and safety of the process, and intensified mass and energy transfer. The mixing time in microdevices is reduced to a few milliseconds because the molecules in the microchannels have a short diffusion path. In this paper, an overview of emulsification processes, the advantages of use of microfluidics in emulsification, and future perspectives of microemulsification are presented.Tradicionalno se emulzije pripremaju primjenom jakih smičnih sila koje nastaju upotrebom statičkih miješala, homogenizatora ili primjenom ultrazvuka. Tako proizvedene emulzije osjetljive su na promjenu procesnih uvjeta. Primjena jakih sila i povišenih temperatura može značajno utjecati na komponente emulzija i njihovu konačnu stabilnost. Primjena protočnih mikrosustava pokazala se učinkovitom alternativnom tehnologijom klasičnim metodama emulgiranja. Male dimenzije mikrouređaja u kombinaciji s kontinuiranom provedbom procesa omogućuje brojne prednosti u odnosu na klasične šaržne procese emulsifikacije koji se provode u većem mjerilu. Male dimenzije mikrouređaja omogućuju lakši transport opreme, bolju kontrolu i sigurnost procesa te intenzivniji prijenos tvari i topline. Vrijeme miješanja u mikrouređajima smanjeno je na nekoliko milisekundi zbog kratkog difuzijskog puta molekula u mikrokanalima. U ovom radu dan je pregled procesa emulgiranja, prednosti primjene protočnih mikrosustava u provedbi procesa emulgiranja te potencijalnih novih područja primjene te tehnologije

Applicability of Foam Mat Drying Process for Production of Instant Cocoa Powder Enriched with Lavender Extract

Postupak sušenja u pjeni jednostavna je i ekonomična zamjena za sušenje raspršivanjem i zamrzavanjem. Zbog brzog sušenja pri niskim temperaturama, očuvanja nutritivne kvalitete i jednostavne rekonstitucije ta je metoda jeftinija. Osnovno načelo procesa je pretvorba tekuće ili polutekuće prehrambene namirnice u pjenu i njezino tankoslojno sušenje. U ovom se radu istražuje mogućnost primjene sušenja u pjeni za proizvodnju instant kakao prahova obogaćenih ekstraktima lavande (Lavandula × hybrida L.). Proces ekstrakcije lavande optimiran je primjenom Taguchijeve metode. Vodeni ekstrakti lavande, dobiveni pri optimalnim uvjetima, dodani su u smjesu bjelanjka, kakao praha, šećera i želatine. Smjese su miješane 4 minute kako bi se dobila stabilna pjena, koja je zatim sušena na temperaturama od 50, 60 i 70 °C i samljevena u prah. Brzine sušenja određene su na osnovi eksperimentalnih podataka dobivenih primjenom modela nelinearne regresije. Također su procijenjena sljedeća svojstva: tečenje, nasipna gustoća, raspodjela veličine čestica, te rekonstitucijska i senzorska svojstva konačnog proizvoda. Na osnovi dobivenih podataka proces sušenja najbolje se mogao opisati pomoću Page-ovog modela. Uzorci sušeni pri nižim temperaturama (t=50 °C) imali su najbolja svojstva tečenja praha i rekonstitucije. Slični su rezultati dobiveni senzorskom analizom: prahovi sušeni pri nižim temperaturama imali su bolji izgled, boju i okus. Dobiveni podaci potvrđuju prikladnost primjene sušenja u pjeni za proizvodnju instant kakao praha obogaćenog ekstraktom lavande.The foam mat drying process is a simple and economical alternative to spray and freeze drying. It is considerably cheaper due to rapid drying at low temperatures, preservation of nutritional quality and easy reconstitution. Basic principle of the process is conversion of a liquid or a semi-liquid foodstuff to foam and thin layer drying of the foam. This study explores the possibility of the foam mat drying for production of instant cocoa powder enriched with lavender (Lavandula × hybrida L.) extracts. The aqueous extraction of lavender was optimized using Taguchi orthogonal array design. Extracts obtained under optimal conditions were added to a mixture of egg white, cocoa powder, sugar and gelatine. Mixtures were blended for 4 min to obtain stable foam which was dried at three different temperatures (t=50, 60 and 70 °C) and milled into a powdered product. Drying rates were obtained from the experimental data using nonlinear model estimation. Flow properties, bulk density, particle size distribution, reconstitution and sensory properties of the final product were also assessed. Based on the obtained data, the drying process was best described by Page’s drying model. Samples dried at lower temperature (t=50 °C) exhibited the best powder flow and reconstitution properties. Sensory analysis resulted in similar findings: powder samples dried at lower temperatures had better appearance, colour and taste. The obtained data confirm the suitability of the foam mat drying for the production of instant cocoa powder enriched with lavender extract