Transformation of Eggshells, Spent Coffee Grounds, and Brown Onion Skins into Value-Added Products

Unlike other wastes from the agri-food industry (straw, corn, cob, stalks, seeds, husks) widely used in biorefineries as feedstock for the production of high-value products (chemicals, biofuels and bioenergy), eggshells, spent coffee grounds, and brown onion skins have not yet found a suitable place in sustainable production, but are mainly landfilled burdening the environment. This paper aims to point out the great potential of eggshells, spent coffee grounds, and brown onion skins as secondary raw materials in sustainable development, with minimal production of waste streams

Transformation of Eggshells, Spent Coffee Grounds, and Brown Onion Skins into Value-Added Products

Unlike other wastes from the agri-food industry (straw, corn, cob, stalks, seeds, husks) widely used in biorefineries as feedstock for the production of high-value products (chemicals, biofuels and bioenergy), eggshells, spent coffee grounds, and brown onion skins have not yet found a suitable place in sustainable production, but are mainly landfilled burdening the environment. This paper aims to point out the great potential of eggshells, spent coffee grounds, and brown onion skins as secondary raw materials in sustainable development, with minimal production of waste streams

Enzymatic Activity in Wheat Seeds of Different Protein Content

We have examined buffer soluble protein content and oxido-reductive and proteolytic enzyme activities of three wheat cultivars with different total protein content. The amount of extracted proteins was lower in wheat with lower total protein content. Activity of glutathione reductase (GR), catalase (CAT), peroxidase (POX) and aspartate protease (phytepsin) was unaffected by differences in total protein content of examined wheat, except in case of peroxidase activity in Srpanjka cultivar. Activity of lypooxigenase (LOX), arginyl and phenylalanyl aminopeptidase (Arg-AP; Phe-AP) was proportionally lower in wheat with lower total protein content. Polyphenoloxidase (PPO) activity was significantly lower, while carboxypeptidase I (CP-I) activity increased with decrease of total protein content. The obtained results indicate that total protein content of wheat affecting the amount of extractable proteins as well as activity of LOX, Arg-AP and Phe-AP, while activities of GR, CAT, POX, PPO, CP-I and phytepsin seem unaffected by total protein content

Aminopeptidaze suhoga i klijajućeg zrna ječma

In processes of barley plant development, various endo- and exopeptidases are involved. To determine the type and number of aminopeptidases that could participate in barley seed germination and tissue growth, their activities in extracts of non-germinated and germinated barley (Hordeum vulgare L. cv. Angora) grains and young tissues have been examined, and some of their properties determined. Aminopeptidases (AP) hydrolysing 2-naphthylamides of various amino acids were present in dry and germinated grains, roots, seedlings and leaves, showing preferences for amino acids phenylalanine (Phe), arginine (Arg), leucine (Leu) and methionine (Met), and lower activity towards alanine (Ala), proline (Pro), glycine (Gly) and histidine (His). Levels and ratios of AP activities changed during germination and tissue development, indicating that APs of different specificities are required at different stages of germination and in young tissues. Thus, the increase of all aminopeptidase activities during the first 24 hours of germination and subsequent decrease show significant involvement in seed primary metabolism restoration. The activities of Arg- and HisAP are equally important in green malt. Seedlings and leaves have pronounced substrate specificity for Phe, Leu, Ala and Pro, while roots have the lowest AP specific activities. From the activities and determined properties, the presence of at least six aminopeptidases optimally active at pH=7.4–8.2 could be discerned in dry and germinated grains, and young tissues of Angora barley. Two aminopeptidases are most probably of broad substrate specificity, three show narrow preference with dominating Leu, Phe, or Pro/His, while one is specific for Arg.U procesu klijanja ječma i razvoja nove biljke sudjeluje čitav niz različitih endo- i egzopeptidaza. Kako bi se odredio tip i broj aminopeptidaza u procesu klijanja i razvoja tkiva, u ekstraktima suhoga i klijajućeg zrna ječma (Hordeum vulgare L. cv. Angora) i ekstraktima klijanjem nastalih tkiva određivana je aktivnost aminopeptidaza, a i neke značajke aminopeptidaza. Aminopeptidaze (AP) koje hidroliziraju 2-naftilamide različitih aminokiselina u suhom i naklijalom zrnu ječma, klijanjem nastalom korjenčiću i izdanku te primarnom listu preferirale su odcjepljivanje fenilalanina (Phe), arginina (Arg), leucina (Leu) i metionina (Met), dok su aktivnosti prema alaninu (Ala), prolinu (Pro), glicinu (Gly) i histidinu (His) bile slabije. Promjene specifičnih aktivnosti i odnosa aktivnosti aminopeptidaza tijekom klijanja i razvoja tkiva ječma naznačuju da su aminopeptidaze različitih specifičnosti potrebne u različitim fazama klijanja i razvoja tkiva. Povećanje aktivnosti aminopeptidaza uočeno je tijekom prva 24 sata klijanja, nakon čega se ona smanjivala, što potvrđuje važnost tih enzima u obnovi primarnog metabolizma zrna, dok su aktivnosti Arg- i HisAP bitne i u zelenom sladu. U izdancima i primarnim listovima izražena je potreba za otcjepljivanjem Phe, Leu, Ala i Pro, dok korjenčići pokazuju najslabije specifične aktivnosti AP. Na osnovi AP aktivnosti te određenih karakteristika AP, može se pretpostaviti da suho i klijajuće zrno ječma Angora, a i tkiva nastala klijanjem, sadrže najmanje 6 različitih aminopeptidaza optimalno aktivnih pri pH=7.4-8.2. Dvije su aminopeptidaze najvjerojatnije specifične za različite supstrate, a tri za Leu, Phe ili Pro/His, dok je jedna specifična samo za Arg

Accumulation of Amadori and Maillard Products in Wheat Seeds Aged under Different Storage Conditions

Occurrence of protein modification by Amadori and Maillard reactions in wheat seeds during ageing at different temperatures and relative humidities (RH) has been investigated over 12 month period. Spectrofluorimetric determination of Maillard products of partially purified proteins extracted from aged seeds revealed increase of protein fluorescence at 325/425 nm (excitation/emission wavelength). The highest increase of Maillard products was observed for seeds aged at 40 °C, RH = 45 %, followed by storage at 25 °C, RH = 45 % and storage at warehouse conditions (10–30 °C, RH = 40–70 %), while seeds kept at 4 °C, RH = 40 % did not show significant accumulation of Maillard products. Similar pattern of accumulation were observed for Amadori products, except for seeds aged at 40 °C, RH = 45 %, where products decreased after 270 days of storage. Obtained data indicate that a wheat seed ageing during storage is associated with protein modification by Amadori and Maillard reactions. However, the contribution of these reactions varies under different storage conditions

Quality Parameter Changes in Wheat Varieties During Storage at Four Different Storage Conditions

Changes in seed quality parameter of three wheat varieties during one year storage at four different storage conditions, were studied. Applied storage conditions adversely affected quality changes in wheat seeds during one year storage. The most pronounced changes were observed for seeds kept at 40°C, RH = 45%, followed by seeds stored at 25°C, RH = 45%, while seeds kept at 4°C, RH = 45% or at warehouse conditions mostly showed minimal or statistically insignificant changes. Elevated temperature of seed storage caused a significant decrease of starch content, hectoliter weight, and wet gluten content, accompanied with increase in fl our acidity, and fluctuating in Zeleny sedimentation value. The intensities of observed changes showed strong dependence on wheat variety

COMPARATIVE ELECTROPHORETIC PATTERNS OF ALBUMINS/ GLOBULINS EXTRACTED FROM DRY GRAINS AND GREEN MALTS OF BARLEY VARIETIES

Ispitana je mogućnost primjene različitih elektroforetskih metoda razdvajanja albumina/globulina slijeđenih nespecifičnim bojanjem proteina, te specifičnom detekcijom glikoproteina i aminopeptidaza za razlikovanje sorti ječma. Albumini/globulini ekstrahirani iz suhoga zrna i zelenoga slada šest sorti ječma razdijeljeni su poliakrilamid gel elektroforezom nativnih uzoraka (10 % T, pH=8,9), poliakrilamid gel elektroforezom u prisutnosti natrijeva dodecil-sulfata te izoelektričnim fokusiranjem u gradijentima pH 3,5-9,5 i pH 4,0-6,5. Ekstrakti proteina iz suhoga zrna davali su bolje rezultate od onih iz zelenoga slada. Rezultati upućuju da bi razdjeljivanje albumina/globulina pomoću SDS-PAGE i izoelektričnoga fokusiranja u gradijentu pH 3,5-9,5 slijeđeno bojanjem proteina pomoću Coomassie Blue moglo poslužiti za razlikovanje hrvatskih sorti ječma. Sortu Angora moguće je, nedvojbeno, razlikovati od ostalih sorti koje se mogu grupirati u skupine kako slijedi: Rodnik/Sladoran, Barun/Rex te sorta Martin. Bojanje glikoproteina ne osigurava razlikovanje ispitanih sorti. Detekcija aktivnosti aminopeptidaze široke specifičnosti, aminopeptidaze koja preferira fenilalanin i leucin, te arginil-aminopeptidaze po provedenom elektroforetskom razdvajanju nije se pokazala pogodnom metodom za razlikovanje ispitanih sorti ječma.Applicability of electrophoretic separations of albumins/globulins, followed by nonspecific protein staining and specific glycoprotein and aminopeptidase detection has been examined for barley variety discrimination. Albumins/globulins extracted from dry grains and green malt of six barley varieties were separated by polyacrylamide gel electrophoresis (10 % T, pH=8.9) of native and sodium dodecyl sulfate denatured proteins, and by isoelectric focusing in pH gradient of 3.5-9.5 and 4.0-6.5. Analysis of dry grain extracts gave better results than green malt extracts. Obtained data indicate that SDS-PAGE of albumins/globulins and IEF in pH gradient 3.5-9.5 followed by Coomassie Blue staining could be useful in Croatian barley variety discrimination. Angora barley could be clearly distinguished from the other varieties which were grouped as follows: Rodnik/Sladoran, Barun/Rex, and Martin. Glycoprotein patterns did not improve the recognition of individual varieties. Broad specificity, phenylalanine and leucine preferring, and arginine specific aminopeptidase were not found as applicable markers for discrimination of examined barley varieties

RAZLIKOVANJE HRVATSKIH SORTI JEČMA SDS-POLIAKRILAMID ELEKTROFOREZOM U GRADIJENT GELU I ELEKTROFORETSKIM FOKUSIRANJEM HORDEINA EKSTRAHIRANIH IZ SUHOGA ZRNJA I ZELENOGA SLADA

Applicability of polyacrylamide gel electrophoresis and isoelectric focusing of hordeins for discrimination of six two-rowed winter barley varieties (Angora, Sladoran, Rodnik, Rex, Martin and Barun) has been investigated. Hordeins extracted from dry grains and green malt of barley varieties were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis in gradient gel of 8-18% T, and by isoelectric focusing in pH gradient of 3.5-9.5 and 5.5-8.5, respectively. In all separation experiments better resolution of proteins was achieved with dry grain extracts, than with malt extracts. Angora, Sladoran and Martin variety could be distinguished from other varieties by differences in hordein patterns obtained by gradient gel SDS-PAGE (8-18% T), and Angora, Sladoran, Martin and Rodnik by isoelectric focusing in pH gradient 5.5-8.5.Ispitana je mogućnost primjene gel elektroforeze i izoelektričnoga fokusiranja hordeina za razlikovanje šest sorti ozimoga dvorednoga ječma (Angora, Sladoran, Rodnik, Rex, Martin, Barun). Hordeini ekstrahirani iz suhoga zrnja i zelenoga slada ječma razdvajani su pomoću SDS- poliakrilamid-gel elektroforeze u gradijentu od 8-18% T i pomoću izoelektričnoga fokusiranja u gradijentima pH 3,5-9,5 i pH 5,5-8,5. U svim pokusima elektroforetskoga razdvajanja ekstrakti proteina iz suhoga zrna davali su bolje rezultate od onih iz zelenoga slada. Sorte Angora, Sladoran i Martin mogle su se razlikovati međusobno i od drugih sorti po elektroforetskome profilu svojih hordeina dobivenih SDSPAGE u gradijent gelu (8-18% T), a sorte Angora, Sladoran, Martin i Rodnik pomoću IEF u pH gradijentu 5,5-8,5

Quality Parameter Changes in Wheat Varieties During Storage at Four Different Storage Conditions

Changes in seed quality parameter of three wheat varieties during one year storage at four different storage conditions, were studied. Applied storage conditions adversely affected quality changes in wheat seeds during one year storage. The most pronounced changes were observed for seeds kept at 40°C, RH = 45%, followed by seeds stored at 25°C, RH = 45%, while seeds kept at 4°C, RH = 45% or at warehouse conditions mostly showed minimal or statistically insignificant changes. Elevated temperature of seed storage caused a significant decrease of starch content, hectoliter weight, and wet gluten content, accompanied with increase in fl our acidity, and fluctuating in Zeleny sedimentation value. The intensities of observed changes showed strong dependence on wheat variety