Utjecaj prethodne obrade etanolom i ultrazvukom na sušenje ananasa u konvekcijskoj sušari
| Autor: | João Henrique Fernandes da Silva, Otidene Rossiter Sá da Rocha, Shirley Clyde Rupert Brandão, Lívia Dias Campêlo de Freitas, Patrícia Moreira Azoubel |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Water activity
product colour General Chemical Engineering convective drying Thermal diffusivity ascorbic acid carotenoids ethanol ultrasound Industrial and Manufacturing Engineering Food processing and manufacture Matrix (chemical analysis) chemistry.chemical_compound Original Scientific Paper Ethanol Moisture TP368-456 Pulp and paper industry Ascorbic acid chemistry Volume (thermodynamics) askorbinska kiselina karotenoidi konvekcijsko sušenje boja proizvoda etanol ultrazvuk Composition (visual arts) TP248.13-248.65 Food Science Biotechnology |
| Zdroj: | Food Technology and Biotechnology Volume 59 Issue 2 Food Technology and Biotechnology, Vol 59, Iss 2, Pp 209-215 (2021) |
| ISSN: | 1334-2606 1330-9862 |
| Popis: | Research background. Drying represents a viable unit operation for the preservation of food. Convective drying is the most used method for plant materials. However, it can result in negative changes in food nutrient composition, and other quality parameters, besides requiring high energy consumption. Pretreatments can represent an alternative to minimise these negative aspects of dried materials. This work aims to evaluate the use of ethanol and ultrasound before pineapple convective drying and its effect on the product´s colour, water activity, ascorbic acid and total carotenoid contents. Experimental approach. For the pretreatment step, fruit samples were immersed in ethanol solutions of different volume fractions, and experiments were carried out for 10 min with and without using ultrasound (25 kHz). Fruit samples were dried at 60 ºC. A control group (without the pretreatment step) was also dried under the same condition. Semi-theoretical models were used for drying data fitting, and the diffusional model was used to describe the moisture transfer and calculate the effective diffusivity. Water activity, ascorbic acid, total carotenoids and colour analyses were performed. Results and conclusions. The combination of ethanol and ultrasound as a pretreatment reduced the drying time of pineapple. Higher effective moisture diffusivities were obtained when ethanol and ultrasound were applied before drying. The two-term exponential model presented the best fit for drying experimental data. The dried samples had a darker colour than the fresh sample. The pretreatment with ethanol resulted in increased retention of the studied bioactive components. The satisfactory results of this study represent an improvement in the drying process. Novelty and scientific contribution. Ultrasound and ethanol as a pretreatment to convective drying are promising. However, each food matrix has a typical structure and composition. Therefore, the application of the pretreatment in other products or using other conditions is still necessary to deeply understand and explain their effect on the process and the quality of the dried products. Pozadina istraživanja. Sušenje predstavlja održivi postupak konzerviranja hrane, a za sušenje biljnog materijala najčešće se koristi konvekcijska sušara. Međutim, ovaj postupak troši veliku količinu energije i može dovesti do negativnih promjena sastava hranjivih sastojaka i drugih parametara kakvoće hrane. Postupci prethodne obrade mogu umanjiti negativne učinke sušenja. Svrha je ovoga rada bila procijeniti postupak obrade ananasa etanolom i ultrazvukom prije konvekcijskog sušenja, te utvrditi učinak tih postupaka na boju, aktivitet vode, te udjele ukupnih karotenoida i askorbinske kiseline u dobivenom proizvodu. Eksperimentalni pristup. U postupku prethodne obrade uzorci voća uronjeni su u otopinu etanola različitih volumnih udjela tijekom 10 min, s primjenom ultrazvuka (25 kHz) ili bez njega, te su zatim sušeni pri temperaturi od 60 ºC. Kontrolna je skupina (bez prethodne obrade) sušena pri istim uvjetima. Dobiveni su rezultati prilagođeni korištenjem teorijskih kinetičkih modela, a pomoću difuzijskog modela opisan je prijenos vlage te izračunata efektivna difuzivnost vode. Ispitani su sljedeći parametri: aktivitet vode, udjeli askorbinske kiseline i ukupnih karotenoida, te boja dobivenog proizvoda. Rezultati i zaključci. Kombinacijom obrade etanolom i ultrazvuka smanjilo se trajanje sušenja ananasa. Veća je efektivna difuzivnost vlage postignuta primjenom etanola i ultrazvuka prije sušenja. Dvočlani eksponencijalni model najbolje je opisao eksperimentalno dobivene podatke. Sušeni su uzorci imali tamniju boju od svježih uzoraka. Prethodnom obradom etanolom zadržala se veća količina bioaktivnih spojeva. Zadovoljavajući rezultati ovog istraživanja predstavljaju poboljšanje postupka sušenja. Novina i znanstveni doprinos. Obrada etanolom i ultrazvukom prije konvekcijskog sušenja daje obečavajuće rezultate. Međutim, svaki prehrambeni artikl ima svojstvenu strukturu i sastav. Stoga je neophodno produbiti razumijevanje učinaka prethodne obrade na sušenje i kakvoću sušenog proizvoda. |
| Databáze: | OpenAIRE |
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