Kondukcijsko sušenje ploda zemnog orašca (Arachis hypogaea) uzgojenog u Republici Hrvatskoj

master's thesis

• Title (english): Conductive drying of peanut seed (Arachis hypogaea) grown in Croatia
• Author: Dario Stanković
• Mentor: Ana Matin (mentor)
• Committee member: Ana Matin (predsjednik povjerenstva)
• Committee member: Aleksandra Perčin (član povjerenstva)
• Committee member: Vanja Jurišić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Agricultural Technology, Storage and Transport); Zagreb
• Defense date and country: 2018-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Zemni orašac (Arachis hypogaea) je kultura koja ima visok sadržaj masnoća u sjemenki, od 45% do 48%, te se time svrstava među visoko značajne energetske kulture. Široko je rasprostranjen u svijetu: od južne Amerike, Europe, Afrike pa sve do Azije. Plod zemnog orašca je mahuna koja raste ispod zemlje i jedina je mahunarka takve vrste. Zemni orašac se najčešće konzumira u ljudskoj ishrani kao poslastica pod nazivom kikiriki u obliku zasoljenog prženog sjemena pa sve do prerađevine u obliku maslaca. Kako bi se poboljšao kemijski sastav i omogućilo dugotrajnije korištenje, sjemenke zemnog orašca se obrađuju termičkim postupkom kondukcijskog sušenja - tostiranjem koji je ujedno i najčešći ovakav postupak. Tijekom kondukcijskog sušenja mijenja se kemijski sastav sjemena.
Za razliku od sjemena, ljuska zemnog orašca dugo je vremena smatrana isključivo otpadom čije je zbrinjavanje predstavljalo problem. S napretkom tehnologije i širenjem ekološke svijesti otkriveno je i energetsko svojstvo ljuske u vidu alternativnog biogoriva te se ona danas uspješno iskorištava kao ogrjev.
U ovom radu su se istraživale kemijske karakteristike sjemena zemnog orašca. Odredio se sadržaj vode, pepela, masti i škroba. Izmjerena količina masnoća nakon sušenja kretala se od 45% do 46% čime se kikiriki uzgojen u Republici Hrvatskoj svrstava uz bok kulturama uzgojenima u svijetu. Kod ljuske su se utvrđivale energetske karakteristike putem određivanja sadržaja vode, pepela, koksa, fiksnog ugljika i hlapive tvari te gornje ogrjevne vrijednosti s ciljem utvrđivanja sirovinskog potencijala kao biogoriva. Termička obrada kondukcijskim sušenjem provedena je na temperaturama od 150°C, 170°C i 190°C te je izrađen i grafički prikaz sušenja. Ljuska zemnog orašca nakon sušenja je imala nizak postotak vode od 2,56% do 1,33% što je poželjno svojstvo koje ukazuje na njenu ogrjevnu vrijednost. Niska je i količina pepela, od 4,81% do 6,12%, što je također jedan od važnijih parametara pri određivanju kvalitete biomase. Zajedno s nešto višim sadržajem negorivih tvari (koks 16,8% do 17,57% i fiksni ugljik 11,28% do 13,73%) ljuska pokazuje sve karakteristike visokog energetskog kapaciteta.

Abstract (english)

Groundnut (Arachis hypogaea) is a culture that has high fat content in seed, from 45% to 48%, and is thus classified as a highly significant energy crop. It is widespread in the world: from South America, Europe, Africa, all the way to Asia. The fruit of groundnut is a pod that grows below ground and is the only legume of this kind. Groundnut is usually used in human nutrition as a delicacy commonly called peanut in the form of salted fried seeds or processed as a butter. In order to improve its chemical structure and allow for longer use, groundnut is treated by a thermal process of conduction drying – toasting, which is also the most common procedure. During such drying the chemical structure of the seed changes.
Unlike the seed, the groundnut shell has been considered solely as waste whose disposal was a problem for a long time. With the advancement of technology and the awakening of ecological consciousness, the energetic attributes of the shell in the form of alternative biofuel have been discovered. It is successfully used as a fuel for heating today.
In this thesis, the chemical characteristics of groundnut seed were researched. The content of water, ash, fats and starch was determined. The measured amount of fat after drying ranged from 45% to 46%, so the groundnut grown in the Republic of Croatia is ranked alongdside by the crops grown in the world. In the shell, energy characteristics were researched with the aim to determine the raw material potential as biofuel. The content of water, ash, coke, fixed carbon and volatile matter as also upper heating values was defined. Thermal processing by conduction drying was carried out at temperatures of 150°C, 170°C and 190°C and the corresponding chart was created. After drying, the groundnut shell had a low water content of 2.56% to 1.33%, which is a desirable characteristic indicating its calorific value. The ash content is also low and it ranged from 4.81% to 6.12%. It is also one of the most important parameters in determining biomass quality. Along with higher content of non-flammable substances such as coke (16.8% to 17.57%) and fixed carbon (11.28% to 13.73%) the shell shows all the characteristics of high energy capacity.

• Keywords: zemni orašac; kikiriki; Arachis hypogaea; ljuska; sjeme
• Keywords (english): groundnut; peanut; Arachis Hypogaea; shell; seed
• Language: croatian
• URN:NBN: urn:nbn:hr:204:017733
• Study programme: Title: Organic Agriculture with Agrotourism; Study programme type: university; Study level: graduate; Academic / professional title: magistar / magistra inženjer/inženjerka ekološke poljoprivrede i agroturizma (magistar / magistra inženjer/inženjerka ekološke poljoprivrede i agroturizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Repository: Repository Faculty of Agriculture University of Zagreb
• Created on: 2018-10-12 09:10:44