Kultuurmarjade koristusjärgse töötlemise tehnoloogia

A Thesis for applying for the degree of Doctor of Philosophy in Engineering SciencesBlueberries belong to a group of horticultural products that have one of greatest growth potentials in Estonia. Modern post-harvesting processing lines handle various operations, but, one of these is the processing of blueberry fruits that are harvested by a berry rake or by mechanical harvesting, where they are fractionated for industrial and table blueberry fruits, although such equipment may be too expensive for small and medium-sized farmers. The aim of this thesis was to increase the productivity, Ws, of the blueberry fruits fractionation equipment by increasing the usage factor of total work time, τ, which depends upon the required adjusting time, ta, and ease of adjustment when changing the cultivar of the processed blueberry fruit. This doctoral thesis is based on four original publications and two intellectual properties. This thesis also concentrated mainly on postharvest processing technology for cultural blueberries that have been grown on small or medium-sized farms. During the process of completing this thesis, an overview was compiled of the available literature in regard to the topic in question - the mathematical modelling of the dimensional characteristics of the blueberry fruit. One example of the findings was, that the most accurate evaluations for the volume of the blueberry fruit, Vb, were obtained when this was estimated using mathematical equations that take into account the mass of the blueberry fruit, mb, and the mass of the blueberry fruit, mb, can be estimated using mathematical equations that take into account the geometric dimensions of the blueberry fruit. During tests, the volume parameter, εv, of the blueberry fruit remained within the range εv = 0.54–0.92 mg mm–3 and the shape factor, εs, of the blueberry fruit remained within the range εs = 0.67–0.96. This indicated that the blueberry fruit is oblate in shape. Based on the information obtained from the literature overview, the principle structure of the MPC was proposed for small or medium-sized blueberry farms. During the development of post-harvest technology for blueberry fruits, the belt sorter was selected as being the most suitable fractionation device for the MPC. In order to decrease the time required to adjust the belt sorter, ta, and to increase the productivity of the belt sorter, Ws, two novel technical solutions were introduced to make the belt sorter adjustable (patent 05642 B1, for the 1st generation solution and patent EE 05798 B1, for the 2nd generation solution). Test results and calculations with parameters given in the discussion section of the current thesis showed that adding the 1st generation solution to the belt sorter would increase the productivity of the belt sorter, Ws, by 48.2 kg h-1. The technical peculiarities of the 1st and 2nd generation solutions were studied through comparative tests. Test results showed that the 2nd generation solution has some technical benefits. For example, the average backlash B2 value for the 2nd generation solution with 3Dprinted key structure components was smaller than for the 1st generation solution by a total of 8.22 mm. CNC milled and turned key structure components for the 2nd generation solution reduced even further the average value for the backlash B2. Thanks to this, the belt sorter prototype with its 2nd generation CNC solution was used in fractionation tests. Test results showed that the overall uniformity, K, of fractionated fractions was K = 82.67%, and the decrease in uniformity, K, of fractionated fractions was connected to an increase in the width, wb, of the fractionation slot between the belt sorter’s belts. Mostly it influenced the uniformity, K, of the larger blueberry fruits fraction. According to the results obtained and the complex construction of the 2nd generation solution, the upgraded 1st generation solution was developed, lowering the value of the backlash B2 by 3.01 mm on average when compared to the 1st generation solution. Additional fractionation tests were carried out in order to test the upgraded 1st generation solution. For that purpose, the belt sorter was used with the length, lf ,of its fractionation area increased and an option added to change the inclination angle of the fractionation area, a. Test results showed that the improvements raised the uniformity, K, of the third fraction (the fraction of large blueberry fruits) by 35% when compared to previous results. The greatest novelties in this thesis are the determined connections between the dimensional characteristics of blueberry fruits, the proposed blueberry post-harvest processing technology for small and medium-sized blueberry farms, and the patented technical solutions which will make the belt sorter adjustable.Mustikad kuuluvad nende marjade hulka, mille kasvatamist peetakse Eestis kõige perspektiivikamaks. Marjakammiga korjatud või masinkoristatud mustikate nüüdisaegsed koristusjärgsed töötlemisliinid, kus lisaks muudele toimingutele sorteeritakse mustikad suuruse järgi tööstusmarjaks ja lauamarjaks, ei pruugi olla taskukohased mustikaid kasvatavate keskmise ja väikese suurusega ettevõtete jaoks. Doktoritöö eesmärk oli suurendada mustikasorteeri tootlikkust Ws, suurendades kasulikku tööaega ts, mis sõltub mustikasordi vaheldumisel mustikasorteeri ümberseadistamisele kuluvast ajast ta ja ümberseadistamise lihtsusest. Töö põhineb autori neljal publikatsioonil ja autori kahel patendil. Käesoleva doktoritöö raames uuriti väikese ja keskmise suurusega mustikakasvatustes kasvatatud mustikate koristusjärgset töötlemistehnoloogiat. Doktoritöö raames koostati kirjanduse ülevaade ning modelleeriti mustikamarja matemaatiliselt. Näiteks leiti, et mustika marja mahtu on võimalik hinnata kõige täpsemalt selle massi järgi ja mustika marja massi on võimalik kõige täpsemalt hinnata selle gabariitmõõtmete järgi. Käesolevas doktoritöös jäi mustika marja kujutegur vahemikku εs = 0,67–0,96 ja mahuparameeter piiridesse εv = 0,54–0,92 mg mm–3. Mustikate koristusjärgse töötlemistehnoloogia arendamisel valiti sobilikuks mustikate sorteerimisseadmeks rihmsorteer, mille ümberseadistamise aja vähendamiseks marjasordi vahetamisel ja sel viisil rihmsorteeri tootlikkuse suurendamiseks arendati välja reguleeritava rihmatrumli kaks versiooni (15.04.2013 avaldatud patent EE 05642 B1 ehk I põlvkond ja 15.09.2017 avaldatud patent EE 05798 B1 ehk II põlvkond). Katsetulemuste ja arvutustes kasutatud algandmete põhjal leiti, et reguleeritava rihmatrumli lisamisega suurenes rihmsorteeri tootlikkus Ws 48,2 kg h-1 võrra. I ja II põlvkonna reguleeritava rihmatrumli tehniliste iseärasuste väljaselgitamiseks võrreldi neid erinevates katsetes ja leiti, et II põlvkonna reguleeritaval rihmatrumlil on teatud tehnilised eelised. Näiteks oli 3D printeriga prinditud detailidega II põlvkonna rihmatrumli rihmaseibide pendellõtk B2 keskmiselt 8,22 mm võrra väiksem võrreldes I põlvkonna rihmatrumli rihmaseibide pendellõtkuga. CNC lõiketöötlemise teel valmistatud II põlvkonna detailidega vähenes pendellõtk B2 veelgi. Seetõttu viidi mustikate sorteerimiskatsed läbi rihmsorteeriga, millele oli paigaldatud II põlvkonna reguleeritav rihmatrummel CNC lõiketöötlemise teel valmistatud detailidega. Sorteerimiskatsete tulemuseks saadi, et sorteeritud marjafraktsioonide keskmine puhtus oli 82,67%. Katsetulemuste analüüsimisel selgus, et rihmsorteeri fraktsioneerimispilu laiuse suurendamine II põlvkonna reguleeritava rihmatrumliga mõjutab sorteeritud marjafraktsioonide puhtust negatiivselt, kusjuures kõige enam avaldas see negatiivset mõju suurte marjade fraktsiooni puhtusele. Katsetulemuste ja II põlvkonna reguleeritava rihmatrumli tehniliste iseärasuste tõttu otsustati täiendada I põlvkonna reguleeritava rihmatrumli tehnilist lahendust, mille tulemusena vähenesid rihmaseibide pendellõtkud B2 keskmiselt 3,01 mm võrreldes esialgsete I põlvkonna pendellõtkudega B2. Lisaks suurendati rihmsorteeri sorteeriva ala pikkust lf ning lisati võimalus muuta sorteeriva ala kaldenurka kuni α = 10 kraadi. Mustikate sorteerimise täiendavad katsed näitasid, et eelnimetatud täiendustega suurenes suurte marjade fraktsiooni puhtus võrreldes esialgsete tulemustega 35%. Doktoritöö uudsusteks on tulemused, mis saadi mustikamarja matemaatilisel modelleerimisel, välja pakutud mustikate koristusjärgne töötlemistehnoloogia väikese ja keskmise suurusega mustikakasvatustele ning rihmsorteeri reguleeritava rihmatrumli kaks patenteeritud tehnilist lahendust.Publication of this thesis is supported by the Estonian University of Life Sciences

EXPLORATION OF THE POSSIBILITIES FOR THE PRODUCTION OF TABLEWARE FROM THE BRAN OF VARIOUS CEREALS

Biodegradable and compostable tableware is significantly more environment and nature friendly than disposable tableware and drinkware made of plastic. Tableware made of wheat bran, but also corn and rice bran is already commercially available. It is reasonable to use the by-products of the milling of also other cereals, like rye bran, barley bran and oat bran, for the production of tableware. The aim of this research was to explore the possibilities for the production of tableware and drinkware from the by-products of the milling of wheat and also other cereals like rye and oat bran. In order to achieve the aim, compacts were moulded from rye bran and oat bran and mixtures of bran (wheat bran and rye bran) using various work modes. The moulding of the compacts included different temperatures of the mould, moulding durations and compressive forces. The mechanical properties like density and flexural strength of the compacts were determined and the compostability of the compacts was studied. The test bodies were placed inside a compost bin to check their compostability and to determine the duration of composting.Biodegradable and compostable tableware is significantly more environment and nature friendly than disposable tableware and drinkware made of plastic. Tableware made of wheat bran, but also corn and rice bran is already commercially available. It is reasonable to use the by-products of the milling of also other cereals, like rye bran, barley bran and oat bran, for the production of tableware. The aim of this research was to explore the possibilities for the production of tableware and drinkware from the by-products of the milling of wheat and also other cereals like rye and oat bran. In order to achieve the aim, compacts were moulded from rye bran and oat bran and mixtures of bran (wheat bran and rye bran) using various work modes. The moulding of the compacts included different temperatures of the mould, moulding durations and compressive forces. The mechanical properties like density and flexural strength of the compacts were determined and the compostability of the compacts was studied. The test bodies were placed inside a compost bin to check their compostability and to determine the duration of composting

Technology for the Production of Environment Friendly Tableware

From the point of view of environmental protection, it is reasonable to stop using disposable tableware that has been made from polluting plastics and to start using biodegradable and compostable products. Biodegradable and compostable tableware is significantly more environment and nature friendly than disposable plastic tableware and drinkware. The by-products (mostly bran) from the milling of wheat, corn and rice and palm leaves are used for the production of tableware. In the Baltic States, including Estonia, it is reasonable to use wheat bran, rye bran and buckwheat bran and the mixtures of these brans. The aim of this research was to provide the technical and technological know-how for the production of environment friendly disposable tableware and to verify the suitability of the new technological means. In order to achieve the aim, a punch and a die were modelled to produce disposable plates with desired parameters, materials and work modes for the material were chosen and, thereafter, the plates were produced from bran using a physical punch and die and using a suitable moulding mode or temperature and compression duration and using prescribed compressive forces. The mechanical properties like density and flexural strength of the moulded plates were determined