Optimiranje sastava bademovog napitka obogaćenog ekstraktima mirte, lovora i komorača, kao zamjene za mlijeko

Research background. Herbs and spices used in traditional medicine are nowadays increasingly used in combinations to create functional food formulations aimed at treating specific symptoms and disorders. Among herbs originating from the Mediterranean region, extracts of myrtle (Myrtus communis L.), bay leaf (Laurel nobilis L.) and fennel (Foeniculum vulgare Mill.) are traditionally used for gastrointestinal disorders. When considering how to incorporate these extracts into products, dairy-free milk alternatives provide an excellent base with almond-based drinks being among the most popular within this group. Experimental approach. The aim of this study is therefore to optimise the formulation of an almond drink fortified with a 25 % (on dry mass basis) aqueous herbal extract containing myrtle, bay leaf (25 % each) and fennel seed (50 %) extracts. A central composite design with 20 formulations varied the content of φ(aqueous herbal extract)=2–6 %, lecithin as emulsifier 0.15–0.45 and xylitol as sweetener 2–5 % (m/V), while antioxidant activity, total phenolic content and sensory properties were determined as dependent variables. Results and conclusions. The antioxidant activity and total phenolic content of the prepared almond drink formulations increased with the amount of added concentrated aqueous herbal extracts, as did the colour, herbal odour and flavour, bitterness and aftertaste. The addition of lecithin resulted in a darker colour and the sweetness was increased by the xylitol content. All formulations had good overall attractiveness, which increased with higher xylitol content. Novelty and scientific contribution. The current work offers new insights into the optimisation of fortified dairy-free alternatives. The addition of myrtle, bay leaf and fennel seed extracts to almond drink-based formulations resulted in a 12-fold increase in antioxidant activity. Xylitol masks the potential bitterness of the phenolic compounds so that higher amounts of extracts can be added. §Paper was presented at the 11th Central European Congress on Food and Nutrition CEFood2022, Čatež ob Savi, Slovenia, 27-30 September 2022Pozadina istraživanja. Biljke i začini koji se upotrebljavaju u tradicionalnoj medicini se sve više kombiniraju pri razvoju funkcionalnih prehrambenih proizvoda usmjerenih na liječenje specifičnih simptoma i poremećaja. Među mediteranskim biljkama koje se tradicionalno koriste u liječenju poremećaja probavnog sustava, značajno mjesto imaju ekstrakti mirte (Myrtus communis L.), lovora (Laurel nobilis L.) i komorača (Foeniculum vulgare Mill.). Razmatrajući proizvode u koje bi se ovi ekstrakti mogli inkorporirati, zamjene za mlijeko na biljnoj bazi se ističu kao izvrsna osnova, pri čemu su bademovi napitci među najpopularnijima. Eksperimentalni pristup. Svrha je ovog istraživanja bila optimirati sastav bademovog napitka obogaćenog koncentriranim vodenim ekstraktom (sa 25 % suhe tvari), koji sadržava ekstrakte mirte i lovora (po 25 %) i ekstrakt sjemenki komorača (50 %). Centralni kompozitni plan s 20 formulacija sadržavao je različite udjele vodenog ekstrakta biljaka (φ=2–6 %), emulgatora lecitina (0,15–0,45 % m/V) i ksilitola kao sladila (2–5 % m/V), dok su antioksidacijska aktivnost, koncentracija ukupnih fenolnih spojeva i senzorska svojstva napitaka određeni kao zavisne varijable. Rezultati i zaključci. Antioksidacijska aktivnost i koncentracija ukupnih fenolnih spojeva u pripremljenim bademovim napitcima povećavale su se s povećanjem udjela koncentriranog vodenog ekstrakta biljaka, kao i intenzitet boje, miris, biljni okus, gorčina i naknadni okus. Dodatak lecitina rezultirao je tamnijom bojom, a prisutnost ksilitola povećala je slatkoću proizvoda. Svi napitci imali su dobru ukupnu privlačnost, koja se povećavala s povećanjem udjela ksilitola. Novina i znanstveni doprinos. Ovaj rad pruža nove uvide u optimiranje obogaćenih zamjena za mlijeko na biljnoj osnovi. Dodatak ekstrakata mirte, lovora i komorača u bademove napitke rezultirao je 12 puta većom antioksidacijskom aktivnošću. Ksilitol prikriva potencijalnu gorčinu fenolnih spojeva, omogućavajući dodavanje većih količina ekstrakata

Physicochemical Composition, Phenolic Content and Antioxidant Activity of Sour Cherry cv. Marasca During Ripening

Sour cherry cv. Marasca is Dalmatian cultivar from XVI century. Cultivation is limited on the north and central part of Dalmatia and on the part of the islands, where it achieves the best quality of fruit, high content of dry matter and sugar respectively, agreeable aroma and intense color. Sour cherry cv. Marasca is source of biologically active ingredients, organic and inorganic compounds, dietary fibers, aromatic compounds and high content of phenolic compounds, particularly anthocyanins and hormone melatonin. Many epidemiological studies showed that phenolic compounds have antioxidant and anti-inflammatory properties, and they have beneficial effect on human health. Marasca is rich with mentioned compounds. Physicochemical composition (total and soluble dry matter, pH value, total acidity) during ripening of cv. Marasca ecotype Recta (Cerasus marasca recta) grown in Zadar and Split area were determined. Total and soluble dry matter increased and pH value and total acidity showed little change during ripening. The content of phenolic compounds increased during ripening as well as content of anthocyanins, while antioxidant activity decreased with ripening. That indicates there was no correlation between antioxidant activity and content of total phenolic compounds

Effect of accelerated solvent extraction conditions on the isolation of bioactive compounds from fennel (Foeniculum vulgare Mill.) seeds

This study focused to establish the optimal conditions of accelerated solvent extraction (ASE), i.e., temperature, static extraction time and number of extraction cycles, for the isolation of fennel (Foeniculum vulgare Mill.) seeds phenols and pigments using 96% ethanol as an extraction solvent. Hence, extraction conditions of temperature (80 and 110 °C), static extraction time (5 and 10 min) and number of extraction cycle (1, 2, 3 and 4) were varied. Obtained extracts were spectrophotometrically analyzed for the content of total phenols (TP), total chlorophylls (TCHL) and total carotenoids (TCAR). Applied extraction conditions had a significant (p<0.01) influence on the yields of analyzed compounds, except for static extraction time on TCAR (p=0.11). Based on the results of statistical analysis, the highest levels of TP and TCHL were achieved at the most invasive conditions (110 °C/10 min/4 cycles), while shorter period was sufficient to reach the highest TCAR yield (110 °C/5 min/3 cycles). In summary, ASE demonstrated to be effective extraction technique for the isolation of fennel seeds hydrophilic and lipophilic bioactive compounds

Istraživačko-edukacijsko središte Prehrambeno-biotehnološkog fakulteta Sveučilišta u Zagrebu smješteno u Zadru

Godine 2006. osnovano je u okviru Prehrambeno-biotehnološkog fakulteta Sveučilišta u Zagrebu Međunarodno edukacijsko-istraživačko središte locirano u zgradi Fakulteta u Zadru. Za stavljanje u funkciju prostora koji je u to vrijeme bio devastiran i praktički neupotrebljiv osigurana su sredstva uz značajnu participaciju Grada Zadra i Zadarske županije čime je omogućena izgradnja i opremanje laboratorija. Od 2010. godine u Centru se kontinuirano i sustavno provode brojne znanstveno-istraživačke aktivnosti koje obuhvaćaju implementaciju različitih kategorija projekata financiranih iz nacionalnih izvora te najvećim dijelom iz fondova EU. Uspješnom implementacijom projekata ojačan je znanstveno istraživački kapacitet Centra te infrastruktura kroz nabavu sofisticirane tehnološke te analitičke opreme i laboratorijskih uređaja. Također, u Centru se provode i istraživanja vezana uz izradu završnih, diplomskih i doktorskih radova te surednja s gospodarstvom

Influence of Jam Processing Upon the Contents of Phenolics and Antioxidant Capacity in Strawberry fruit (Fragaria ananassa × Duch.)

Seven cultivars of strawberry (Diamante, Elsanta, Honeoye, Madeleine, Marmolada, Miranda and Miss) were analyzed for total phenols (TP), total flavonoids (TF), total nonfl avonoids (TN), total anthocyanins (TA) and antioxidant capacity (AC) before and after low sugar jam production to evaluate their changes after thermal processing. The content of TP, TF and TN were determined according to the Folin-Ciocalteu assay. Anthocyanins were determined by spectral method based on the bisulfite bleaching of monomeric anthocyanins. The antioxidant capacity was evaluated by ,2-diphenyl-1-picrylhydrazil radical (DPPH). Fresh fruits had total phenolics ranging from 251.97 to 713.06 mg gallic acid equivalent GAE/g of dry weight. In all investigated samples, fresh strawberries and jams, nonflavonoids were predominant phenols. Cultivar Honeoye had the highest amounts, while cultivar Miss had the lowest amounts of TP and TN. Cultivar Miranda had TF in the highest concentrations, while the lowest concentrations were found in cultivar Marmolada. TA for investigated cultivars was 63.55-177.71 mg Cy-3-G/100 d.w. with strong differences among cultivars. On the basis of dry weight the processing and heating during jam making generally decreased the contents of TP for 37-70 %. During processing, cultivar Madeleine showed the greatest stability of TP, TN and TF, while cultivar Elsanta showed the greatest anthocyanins stability. In comparison with fresh strawberry fruit, whose antioxidant capacity were in the range of 0.23 mmol TE/kg f.w. to 0.67 mmol TE/kg f.w., the jams also represent a noticeable source of antioxidant compounds, even considering the lower content of phenolic compounds, with the antioxidant capacity of 0.20 mmol TE/kg f.w. to 0.62 mmol TE/kg f.w. Hence, the obtained results showed that besides fresh strawberry fruit, the strawberry jams also possess noticeable content of important bioactive compounds with considerable antioxidant capacity

Antioxidant Activity of Aqueous Tea Infusions Prepared from Oregano, Thyme and Wild Thyme

Različitim metodama istražen je odnos antioksidativne aktivnosti i kemijskog sastava infuza mravinca, timijana i majčine dušice. Spektrofotometrijskim metodama određena je koncentracija ukupnih fenola, flavonoida, katehina i antocijanina. Infuz mravinca imao je najveću koncentraciju ukupnih fenola (12500 mg/L) i flavonoida (9000 mg/L), izraženu kao galna kiselina. HPLC-PDA metodom određivanja polifenolnih spojeva dokazano je da u infuzu ima najviše ružmarinske kiseline (u mg/g), i to 123,11 u infuzu mravinca; 17,45 u infuzu timijana i 93,13 u infuzu majčine dušice. Antioksidativna aktivnost infuza istražena je pomocu četiri metode: metodom izbjeljivanja b-karotena, metodom uklanjanja 2,2\u27-difenil-1- pikrilhidrazil (DPPH) radikala, metodom s reaktivnim spojevima tiobarbiturne kiseline (TBARS metoda) i metodom određivanja indukcijskog vremena oksidacije masti (Rancimat metoda). Rezultati su uspoređeni s prirodnim (askorbinska kiselina i a-tokoferol) i sintetskim antioksidansima - butiliranim hidroksitoluenom (BHT) i butiliranim hidroksianisolom (BHA). Primjenom triju metoda (izbjeljivanjem b-karotena, metodom uklanjanja DPPH radikala i Rancimat metodom) dokazano je da infuza mravinca ima najveću antioksidativnu aktivnost, dok su timijan i majčina dušica pokazali slabiju i relativno sličnu antioksidacijsku aktivnost.Using a multiple-method approach, antioxidant activity of aqueous tea infusions prepared from oregano (Origanum vulgare L. ssp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) were tested in relation to their chemical composition. Total phenolic, flavonoid, catechin and anthocyanin content was determined by spectrophotometric methods. Oregano aqueous tea infusion had the highest amount of total phenols (12 500 mg/L gallic acid equivalent, GAE) and flavonoids (9000 mg/L GAE). Identification of polyphenolic compounds in aqueous tea infusions by HPLC-PDA analysis showed a dominant presence of rosmarinic acid (in mg/g): 123.11 in oregano, 17.45 in thyme and 93.13 in wild thyme. Antioxidant activity of aqueous tea infusions was evaluated using four antioxidative methods (the b-carotene bleaching method (BCB), the 2,2’-diphenyl-1- -picrylhydrazyl (DPPH) radical scavenging method, the thiobarbituric acid reactive species (TBARS assay) and the induction period of lard oxidation (Rancimat assay)). The results were compared with natural (ascorbic acid and a-tocopherol) and synthetic antioxidants, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). Oregano aqueous tea infusion showed the strongest antioxidant activity using three methods (the b-carotene bleaching method, DPPH radical scavening method and Rancimat assay), while thyme and wild thyme showed weaker and relatively similar antioxidant activity

Determination of Flavonoids in Pulp and Peel of Mandarin Fruits

The aim of this study was to determine total flavonoids and individually flavanon glycosides as well as antioxidant capacity in pulp and peel of two mandarin groups, namely Satsuma (Citrus unshiu Marcovitch) cv. Saigon and Clementine (Citrus reticulate var. clementine) cv. Corsica SRA 63. Total flavonoids content was measured using colorimetric method, whereas HPLC-PDA detection was used for the analysis of individual flavanone glycosides (narirutin, naringin and hesperidin). In addition FRAP method was used to determine the antioxidant capacity. The results of colorimetric method showed that there was high concentration of flavonoids in all investigated samples, especially in peels (1156 mg/100 g in Satsuma peel and 804 mg/100 g in Clementine peel). Among the flavonone glycosides, hesperidin, was determined in the highest concentration in both investigated pulps. In peels flavanon glycosides were present in decreasing sequence as follow: narirutin>hesperidin>naringin. According to FRAP method, all samples possess an evident antioxidant capacity especially peels. Correlation between total flavonoids, hesperidin, naringin, narirutin and antioxidant capacity was very high with correlation coefficiants between 0.81 and 0.98

Influence of Jam Processing Upon the Contents of Phenolics and Antioxidant Capacity in Strawberry fruit (Fragaria ananassa × Duch.)

Seven cultivars of strawberry (Diamante, Elsanta, Honeoye, Madeleine, Marmolada, Miranda and Miss) were analyzed for total phenols (TP), total flavonoids (TF), total nonfl avonoids (TN), total anthocyanins (TA) and antioxidant capacity (AC) before and after low sugar jam production to evaluate their changes after thermal processing. The content of TP, TF and TN were determined according to the Folin-Ciocalteu assay. Anthocyanins were determined by spectral method based on the bisulfite bleaching of monomeric anthocyanins. The antioxidant capacity was evaluated by ,2-diphenyl-1-picrylhydrazil radical (DPPH). Fresh fruits had total phenolics ranging from 251.97 to 713.06 mg gallic acid equivalent GAE/g of dry weight. In all investigated samples, fresh strawberries and jams, nonflavonoids were predominant phenols. Cultivar Honeoye had the highest amounts, while cultivar Miss had the lowest amounts of TP and TN. Cultivar Miranda had TF in the highest concentrations, while the lowest concentrations were found in cultivar Marmolada. TA for investigated cultivars was 63.55-177.71 mg Cy-3-G/100 d.w. with strong differences among cultivars. On the basis of dry weight the processing and heating during jam making generally decreased the contents of TP for 37-70 %. During processing, cultivar Madeleine showed the greatest stability of TP, TN and TF, while cultivar Elsanta showed the greatest anthocyanins stability. In comparison with fresh strawberry fruit, whose antioxidant capacity were in the range of 0.23 mmol TE/kg f.w. to 0.67 mmol TE/kg f.w., the jams also represent a noticeable source of antioxidant compounds, even considering the lower content of phenolic compounds, with the antioxidant capacity of 0.20 mmol TE/kg f.w. to 0.62 mmol TE/kg f.w. Hence, the obtained results showed that besides fresh strawberry fruit, the strawberry jams also possess noticeable content of important bioactive compounds with considerable antioxidant capacity

Color Parameters and Total Anthocyanins of Sour Cherries (Prunus cerasus L.) During Ripening

Color is very important indicator of quality of fresh fruit. It also serves for estimating the stage of maturity of fruit. Plant pigments responsible for the color of some kind of fruits are anthocyanins. Anthocyanins are the flavonoids which are present in high amounts in sour cherries. The aim of this study was to determine total anthocyanins and color parameters of sour cherries ‘Cigančica’ and ‘Keleris’ collected in Osijek and Zadar (Croatia) in 2005 during ripening. Color parameters of skin and fl esh of sour cherries were determined with colorimetric CIE LAB method and total anthocyanins were determined by means of high performance liquid chromatography (HPLC) using UV/VIS PDA detector. Total anthocyanin was higher in sour cherries cv. Keleris grown in Zadar than in cv. Cigančica grown in Osijek during ripening although cv. Keleris is light colored genotype. Obtained results suggested that warm Mediterranean climate could have influence on high anthocyanin synthesis during ripening. Analysis of variance showed that stage of ripening did not influence total anthocyanin concentrations, but influenced almost all color parameters. Parameter H° was good indicator of color variation during ripening in both sour cherry cultivars

Effect of Maturity and Geographical Region on Anthocyanin Content of Sour Cherries (Prunus cerasus var. marasca)

Istraživan je utjecaj različitih stupnjeva zrelosti na količinu antocijana i pokazatelje boje u tri ekotipa višnje maraske s dva geografska područja Dalmacije. Antocijani su određivani primjenom HPLC uz UV/VIS PDA detekciju, a boja je plodova određivana tristimulusnim kolorimetrom (sustav CIELAB). Najveća količina antocijana nađena je u svim ekotipovima maraske, i to cijanidin 3-glukozilrutinozid i cijanidin 3-rutinozid, za razliku od pelargonidin glikozida koji je bio u manjim koncentracijama. Tijekom zrenja količina se antocijana nije podjednako mjenjala, ali je u većini ekotipova određena u većim koncentracijama u posljednjem stupnju zrenja (3,18-19,75 g po kg suhe tvari). Stvaranje tamnocrvene, gotovo crne boje u zrelim višnjama maraske uvjetovalo je smanjenje vrijednosti crvene komponente boje (a*), svjetloće (L*) i intenziteta obojenja (C*). Rezultati analize varijance s dva faktora pokazuju da područje uzgoja bitno utječe na povećanje količine pojedinačnih antocijana u višnjama i promjenu vrijednosti parametra boje L* tijekom zrenja. Nadalje, količina ukupnih antocijana u višnjama osobito ovisi o ekotipu i međusobnom utjecaju ekotipa i područja uzgoja.The influence of different stages of maturity on the anthocyanin content and colour parameters in three sour cherry Marasca ecotypes grown in two Dalmatian geographical regions has been studied. Anthocyanins were determined by HPLC-UV/VIS PDA analysis and the colour of fruit flesh and skin was measured by tristimulus colourimeter (CIELAB system). The major anthocyanins in all ecotypes at all stages of maturity were cyanidin 3-glucosylrutinoside and cyanidin 3-rutinoside, whereas pelargonidin glycosides were determined in lower concentrations. During ripening, anthocyanins did not change uniformly, but in most ecotypes they were determined in higher concentrations at the last stage of maturity (3.18 to 19.75 g per kg of dry matter). The formation of dark red, almost black colour in ripe Marasca cherries decreased redness (a*), brightness (L*) and colour intensity (C*). The results of two-way ANOVA test indicated that the growing region significantly influenced the accumulation of individual anthocyanins and L* value during ripening, while ecotype and the interaction between the growing region and the ecotype significantly affected total anthocyanin content of sour cherry