The influence of laurel essential oil treatment on the shelf-life and sensory characteristics of fresh-cut apples during storage

Fresh-cut apples provide consumers convenient, fresh, ready-to-eat product. However such products are susceptible to browning and microbiological spoilage which occurs very quickly after processing. Due to their antimicrobial properties, essential oils have a potential stabilizing effect on fresh-cut products, but could have undesirable effects on their color or taste. The aim of this study was to investigate the effect of laurel essential oil (LEO) treatment at different concentrations (25, 75, 125 and 175 mg L-1) on the shelf-life (aerobic mesophilic bacteria count) and physical (soluble dry metter, pH, color, texture) and sensory characteristics of fresh-cut apples during 10 days of storage at 8 °C. Number of aerobic mesophilic bacteria decreased with the increase of LEO concentration and it slightly increased with the increase of storage time. In general, samples treated with 75 mg L-1 LEO had the lowest and samples treated with 175 mg L-1 LEO the highest soluble dry matter, while pH trend was vice versa. Soluble dry matter, pH, and firmness increased during storage. Apples treated with 75 mg L-1 LEO after 10 days of storage showed the least color change. This study showed that LEO can be used to preserve and enrich sensory characteristics of fresh-cut apples, especially at a concentration of 75 mg L-1. Generally, this LEO concentration can be recommended regarding the results of microbiological and sensory analysis as well as results of soluble dry matter, pH, color parameters and firmness

Smrzavanje smokve u šećernim otopinama: kvaliteta, fenolni sastav i senzorska svojstva tijekom skladištenja

The effect of fig freezing in sugar solution on fig’s quality and sensory traits as well as phenolic content during storage was examined. Fresh figs were frozen without any treatment (control - CON), in sucrose solution (30%) (SUC) and sucrose solution (30%) with ascorbic acid (2%) (SUCAA), and stored at -18 ⁰C for 210 days. Samples were analyzed every seventy days for pH, total soluble solids (TSS), sugars and phenolics composition, skin and pulp color, and they were sensorially evaluated. According to ANOVA, storage time showed significant impact on more analyzed parameters than freezing conditions. CON and SUC had the highest TSS, what was also sensorially detected. SUCAA was evaluated with the lowest scores for sweetness and typical fig flavor followed by the highest score for off-taste, off-flavor and off-odor. Contrary to TSS, individual sugars and phenolics were the lowest in CON. SUCAA showed the most brightener skin and the reddest pulp measured by colorimeter, and sensorially it obtained the highest scores for skin and pulp color. Storage time caused TSS and pH decrease, what reflected sensorially as a decrease of fig taste and flavor, as well as the appearance of off-taste, off-flavor and off-odor was also observed. Contrary, individual sugars and phenolics showed increase during storage, and the lowest amounts were present in CON. In conclusion, after 140 days all figs noticeably lost their desirable attributes, where CON fig was sensorially the best evaluated and SUCAA gained the lowest scores.U radu se pratio utjecaj smrzavanja u otopini šećera na kvalitetu, fenolni sastav i senzorska svojstva smokava tijekom skladištenja. Svježe smokve zamrznute su bez tretmana (kontrola - CON), u otopini saharoze (30%) (SUC) te otopini saharoze (30%) s askorbinskom kiselinom (2%) (SUCAA) te su čuvane pri -18 °C 210 dana. Svakih sedamdeset dana u uzorcima je određivan pH, topljiva suha tvar (TST), sastav šećera i fenola, boja pokožice i pulpe te se provodilo senzorsko ocjenjivanje. Analiza podataka (ANOVA) je pokazala da vrijeme skladištenja ima značajan utjecaj na više parametara u usporedbi s uvjetima smrzavanja. CON i SUC uzorci imali su najviši TST, što se odrazilo na višu senzorsku ocjenu. SUCAA uzorak bio je senzorski ocijenjen s najnižom ocjenom za slatkoću i tipičan okus smokve te s najvišom ocjenom stranog okusa, arome i mirisa. Suprotno TST-u, pojedinačni šećeri i fenoli bili su najniži u CON. Najsvjetlija boja pokožice i najveći udio crvene boje u pulpi izmjereni su kolorimetrom za SUCAA, a tom uzorku je i senzorski boja pokožice i pulpe najbolje ocjenjena. Tijekom skladištenja TST i pH su se smanjivali, što se odrazilo na senzorski lošije ocjenjenu aromu i okus na smokvu, kao i pojavu stranog okusa, arome i mirisa u svim uzorcima. Suprotno tome, pojedinačni šećeri i fenoli pokazali su porast tijekom skladištenja, iako su u najnižoj koncentraciji određeni u CON. Zaključno, nakon 140 dana zamjetno su poželjna senzorska svojstva smokava sve manje izražena, pri čemu je CON najbolje ocijenjen, a SUCAA najlošije

Potato\u27s Nutritional Value and its impact on human health

Budući da svjetska populacija raste, FAO (Organizacija za hranu i poljoprivredu Ujedinjenih naroda) smatra krumpir važnom namirnicom koja bi mogla imati glavnu ulogu kao osnovna hrana sadašnjih i budućih generacija. Krumpir ima veliku važnost u prehrani ljudi iz više razloga: jednostavan način uzgoja, visoki prinosi i potrošnja, prihvatljiva cijena, jednostavni i različiti načini pripreme. Kako se krumpir konzumira u većim količinama, male razlike u nutritivnim sastojcima krumpira imaju velik utjecaj na zdravlje stanovništva. Krumpir je hrana bogata ugljikohidratima (škrobom), dok je udio proteina u krumpiru vrlo nizak, no ima izvrsnu biološku vrijednost od 90 do 100 (u odnosu na referentnu vrijednost proteina jaja koja je 100). Krumpir sadrži vitamin C te neke od vitamina B skupine. Nadalje, jedan je od najpristupačnijih izvora minerala kalija i to u količini koja je značajno veća u usporedbi s namirnicama koje su identificirane kao glavni izvori kalija, poput brokule, banane i naranče. Krumpir sadrži i razne fitonutrijente koji imaju antioksidacijsko djelovanje. Među te važne spojeve koji djeluju na smanjenje slobodnih radikala i time doprinose zdravlju pripadaju fenolne kiseline poput klorogenske i kafeinske, flavonoidi, karotenoidi te mnogi drugi. Kora krumpira sadrži značajnu količinu dijetetskih vlakana. Osim hranjivih sastojaka, gomolji krumpira sadrže i neke nepoželjne tvari, antinutrijente, poput glikoalkaloida solanina i hakonina, ali u zdravim konzumnim krumpirima se nalaze u količinama daleko ispod maksimalno dozvoljenih vrijednosti. Stoga, ovaj rad sažima podatke samo o nutritivnim svojstvima krumpira i njihovom utjecaju na zdravlje ljudi.Since the world population is growing, the FAO (Food and Agriculture Organization of the United Nations) considers potato as an important food that could play a major role as a basic food for present and future generations. It has a great importance in human nutrition for many reasons: easy way of cultivation, high yields and consumption, acceptable price, simple and different ways of preparation. Since the potato is consumed in larger amounts, small differences in potato nutritional composition have major impact on population\u27s health. The potato is a carbohydrate-rich food (starch), while protein content is low but has an excellent biological value of 90–100 (relative to the egg protein reference value of 100). Potato contains vitamin C and several B vitamins. Furthermore, potato represents a good source of potassium in an amount significantly higher in comparison with major food sources of potassium, such as broccoli, bananas and oranges. Many various phytonutrients in potato contribute to antioxidant activity. Phenolic acids such as chlorogenic and caffeic acid, flavonoids, carotenoids, and many other compounds belong to these important compounds that reduce free radicals effect and thus contribute to health. The skin provides substantial amount of dietary fibers. Besides nutrients, potato tubers also contain some undesirable substances, antinutrients, glycoalkaloids solanine and chaconine, but in healthy consumer potatoes they are found in quantities notably below the maximum levels. Therefore, this paper summarizes only the data on the nutritional properties of potato and their effect on human health

Fizikalna, kemijska i senzorska karakterizacija svježe rezanog i prženog krumpira s prevlakama od hidrokoloida i biljnih ekstrakta

SUMMARY Research backgroundRecently, natural plant extracts have been used to increase the nutritional value of food and to potentially reduce the absorbed fat and the formation of acrylamide in fried foods. Literature data on the use of edible polymers with nettle or olive leaf extracts are scarce. Experimental approachThe effect of novel coatings on colour, fat absorption, phenolic and sugar content, and acrylamide formation in deep-fat-fried fresh-cut potatoes was evaluated. Extracts of olive and nettle leaves were incorporated in carboxymethyl cellulose (CMC) and gum arabic, used as coatings for potatoes and applied before frying. This aimed to improve the nutritional quality of deep-fat-fried fresh-cut potatoes. Results and conclusionsEnrichment of the edible coatings with extracts resulted in a significant change in the visible colour of the potatoes before frying. Significant effect of the extract amount on the sensory characteristics of potatoes was also observed. Most importantly, the perception of characteristic potato odour and taste was not significantly affected by the coating. Although higher amounts of the extract (1.5%) resulted in higher phenolic mass fraction in fried potatoes, the sensory scores decreased. After frying, fat mass fraction in the coated potatoes was reduced by about 15% compared to the uncoated samples. The type of extract affected the total sugar mass fraction in fried potatoes, which was lower in the samples with coatings enriched with olive leaf than in those with nettle leaf. Only gum arabic coating had a reducing effect on acrylamide mass fraction by 17%. Based on all the obtained results, CMC and gum arabic coatings did not influence sensory properties, so they can be recommended as carriers of functional compounds or as a frying pre-treatment for potatoes with favourable effect on fat and acrylamide content. Novelty and scientific contributionThe knowledge obtained in this study can be exploited for preparation of coatings with functional compounds used as a pre-treatment for fried food with favourable effect on fat and acrylamide content.Pozadina istraživanja. Iako se prirodni ekstrakti iz biljaka posljednjih godina koriste za povećanje nutritivne vrijednosti hrane te moguće smanjenje apsorpcije masnoće i nastanka akrilamida u prženoj hrani, malo je podataka u literaturi o uporabi jestivih polimera s ekstraktima koprive ili lista masline. Eksperimentalni pristup. Procijenjen je učinak novih jestivih prevlaka na boju, upijanje masti, udjele fenola i šećera te nastanak akrilamida u svježe rezanom i prženom krumpiru. Ekstrakti lišća masline i koprive ugrađeni su u karboksimetilcelulozu i gumu arabiku te upotrijebljeni kao premazi za krumpir. Svrha je postupka bila poboljšati nutritivnu kakvoću svježe rezanog prženog krumpira. Rezultati i zaključci. Obrada krumpira jestivim prevlakama obogaćenim ekstraktima znatno je promijenila boju krumpira prije prženja. Također je uočen značajan utjecaj količine ekstrakta na senzorska svojstva krumpira. Prevlaka nije bitno utjecala na percepciju karakterističnog mirisa i okusa krumpira. Iako su veće količine ekstrakta (1,5 %) rezultirale većim udjelom fenola u prženim krumpirima, to je negativno utjecalo na senzorska svojstva. Nakon prženja, udjel masti u krumpirima s prevlakama smanjen je za otprilike 15 % u usporedbi s uzorcima bez prevlaka. Vrsta ekstrakta utjecala je na maseni udjel ukupnih šećera u prženom krumpiru, koji je bio niži u uzorcima s prevlakama obogaćenim listom masline nego u onima s listom koprive. Jedino je prevlaka od gume arabike smanjila maseni udjel akrilamida za 17 %. Na osnovi ukupnih rezultata može se zaključiti da karboksimetil celuloza i guma arabika nisu utjecale na senzorska svojstva, pa se mogu preporučiti kao nositelji funkcionalnih spojeva ili upotrijebiti za obradu krumpira prije prženja, što povoljno utječe na udjele masti i akrilamida u njima. Novost i znanstveni doprinos. Spoznaje dobivene ovim istraživanjem mogu se iskoristiti u pripremi prevlaka s funkcionalnim spojevima koje se koriste u prethodnoj obradi pržene hrane s povoljnim učinkom na udjele masti i akrilamida

Utjecaj UV-C zračenja na trajnost svježe rezanog krumpira i njegova senzorna svojstva nakon termičke obrade

Research background. Potato tissue is damaged during fresh-cut production, which makes fresh-cut potato susceptible to the quality loss and microbiological spoilage. At the same time, such products are desirable due to their convenience; however, they are extremely sensitive and have short shelf life. The main challenge of the fresh-cut potato industry is to find possibilities to overcome these drawbacks. UV-C treatment, known for its antibacterial activity, is a promising technique and it shows a potential to improve shelf life of fresh-cut potato products. Experimental approach. The influence of the UV-C treatment on the safety and quality, as well as sensory traits of fresh-cut potato (Solanum tuberosum L. cv. Birgit) during storage was examined. For this purpose, 0-, 3-, 5- and 10-min UV-C irradiation was applied on vacuum-packed potato slices pretreated with sodium ascorbate solution. During 23 days of storage at (6±1) °C, microbiological, physicochemical and sensory properties of raw samples were monitored, along with sensory properties of boiled and fried fresh-cut potatoes. Results and conclusions. The 5- and 10-min UV-C treatments significantly reduced microbial growth, increased total solids and lightness (L*), and positively affected odour and firmness of raw potatoes. Cooked UV-C-treated samples were described with more pronounced characteristic potato odour and taste. Overall, UV-C-treated fresh-cut potato retained its good quality and sensory traits up to 15 days at (6±1) °C. Novelty and scientific contribution. To the best of our knowledge, this is the first scientific article dealing with the effect of UV-C light on durability (safety, quality and sensory traits) of fresh-cut potato cv. Birgit and its suitability for boiling and frying. In general, UV-C treatment is a known antimicrobial technique, but its application on fresh-cut potato is poorly explored. Results confirmed that vacuum-packed fresh-cut potato treated only with UV-C and sodium ascorbate as anti-browning agent, without the addition of chemical preservatives, had twofold longer shelf-life at (6±1) °C than the fresh-cut potato not treated with UV-C. Fresh-cut potato treated with UV-C retained good overall quality and sensory properties either raw, boiled or fried. Results of this study could also be useful for producers in terms of potential UV-C application as a strategy for prolonging the shelf-life of fresh-cut potato.Pozadina istraživanja. Tijekom proizvodnje svježe rezanog krumpira dolazi do oštećenja tkiva krumpira, što ga čini osjetljivim na gubitak kakvoće i mikrobiološko kvarenje. Istodobno, takvi su proizvodi poželjni zbog svoje praktičnosti, no izrazito su osjetljivi i imaju kratki rok trajanja. Glavni izazov industrije svježe rezanog krumpira je pronaći mogućnosti za prevladavanje ovih nedostataka. Obrada UV-C zrakama, poznatima po svom antibakterijskom djelovanju, je obećavajuća tehnika i pokazuje potencijal za poboljšanje trajnosti svježe rezanih proizvoda od krumpira. Eksperimentalni pristup. Ispitivan je utjecaj UV-C zraka na sigurnost i kakvoću, kao i senzorna svojstva svježe rezanog krumpira (Solanum tuberosum L. cv. Birgit) tijekom skladištenja. U tu svrhu primijenjeno je 0-, 3-, 5- i 10-minutno UV-C zračenje na vakuumirane kriške krumpira prethodno obrađene otopinom natrijevog askorbata. Tijekom 23 dana skladištenja na (6±1) °C praćena su mikrobiološka, fizikalno-kemijska i senzorna svojstva sirovih uzoraka, te senzorna svojstva kuhanog i prženog svježe rezanoga krumpira. Rezultati i zaključci. Obrada UV-C zrakama u trajanju od 5 i 10 minuta značajno je smanjila rast mikroba, povećala ukupnu suhu tvar i svjetlinu (L*), te pozitivno utjecala na miris i čvrstoću sirovog krumpira. Kuhani uzorci tretirani UV-C zrakama opisani su kao uzorci s izraženijim karakterističnim mirisom i okusom krumpira. Sveukupno, svježe rezani krumpir tretiran UV-C zrakama zadržao je svoju dobru kakvoću i senzorna svojstva do 15 dana na (6±1) °C. Novina i znanstveni doprinos. Koliko je nama poznato, ovo je prvi znanstveni članak koji se bavi učinkom UV-C svjetla na trajnost (sigurnost, kakvoću i senzorna svojstva) svježe rezanog krumpira cv. Birgit i njegovu prikladnost za kuhanje i prženje. Općenito, obrada UV-C zrakama je poznata antimikrobna tehnika, ali je njegova primjena na svježe rezani krumpir slabo istražena. Rezultati su potvrdili da svježe rezani krumpir pakiran u vakuumu i tretiran samo UV-C zrakama i natrijevim askorbatom kao sredstvom protiv posmeđivanja, bez dodatka kemijskih konzervansa, ima dvostruko dužu trajnost pri (6±1) °C od svježe rezanoga krumpira koji nije tretiran UV-C zrakama. Svježe rezani krumpir tretiran UV-C zrakama zadržao je dobru ukupnu kakvoću i senzorna svojstva, kako sirov tako i kuhan ili pržen. Rezultati ovog istraživanja mogli bi biti korisni i proizvođačima u smislu moguće primjene UV-C svjetla kao strategije za produljenje trajnosti svježe rezanog krumpira

Multi-elemental composition and antioxidant properties of strawberry tree (Arbutus unedo L.) honey from the coastal region of Croatia: Risk-benefit analysis

The concentration of 23 major and trace elements, total phenolic content (TPC) and 1, 1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity were determined in nine samples of strawberry tree honey and compared to other types of unifloral honeys. The most abundant elements in strawberry tree honey were potassium, calcium, magnesium and sodium, ranging between 1276 and 2367, 95.2-154, 14.4- 74.4 and 13.4-64.3 mg/kg, respectively. Strawberry tree honey had generally higher TPC (range: 0.314-0.522 g GA/kg) and DPPH (1.94- 4.45 mM TE/kg) compared to other analysed unifloral honeys. A strong positive relationship was found between TPC and DPPH, TPC and concentration of homogentisic acid (HGA), chemical marker of strawberry tree honey, and between DPPH and HGA. Regarding daily intake of essential elements, strawberry tree honey can be considered nutritionally richer than the majority of unifloral honeys available in Croatia, while contribution to tolerable intake set for potentially toxic elements was very low, corresponding to pristine areas

Utjecaj UV-C zračenja i visokoga hidrostatskoga tlaka na trajnost i kvalitetu minimalno procesiranoga krumpira (Solanum tuberosum L.)

The aim of this study was to examine the effects of different UV-C doses and high hydrostatic pressure (HHP) conditions on the safety and quality of minimally processed (fresh-cut) potatoes (FCP), and on the sensory properties of raw and thermally treated FCP, while observing the changes during storage. Based on the obtained results, the goal was to compare the effects of optimal UV-C and HHP treatment, as well as their combination, on the properties of FCP. In the first and second part of the research, FCP was treated with a 2% sodium ascorbate solution (SA) and vacuum packed (VP), treated with UV-C (0, 3, 5 and 10 min), and stored (23 days/6 °C). In the third part, FCP was treated with HHP (400 MPa/0, 3, 5 and 10 min) in vessels containing SA solution, VP and stored. In the fourth part, the samples were prepared as in the first part and treated: UV-C (5 min), HHP (400 MPa/3 min) and combined: UV-C (5 min)/HHP (400 MPa/3 min). 5- and 10-min UV-C treatments effectively slowed the growth of aerobic mesophilic bacteria during storage and positively affected the color and odor of raw FCP, while the thermally treated samples had a more pronounced odor and taste. The UV-C decreased the content of chlorogenic acid (CA) in raw FCP. A 5-min UV-C treatment increased the content of reducing sugars (RS) in raw and acrylamide in fried FCP, which was below the suggested limit. Thermal treatment reduced the content of CA and RS. The UV-C treated FCP maintained safety, quality and sensory properties for 15 days. Due to the similar antimicrobial effect of 5- and 10-min UV-C treatments and to save energy, 5-min UV-C was chosen for further investigations. 10-min HHP treatment significantly reduced the bacteria count. The 5- and 10-min treated samples had lower sensory scores, and showed texture damage during frying. The 3-min treatment resulted in significantly slower bacterial growth during storage and lower sensory scores for the boiled and fried FCP compared to control. For further tests, a 3-min HHP was chosen, but in VP without liquid. When comparing UV-C, HHP and UVC/HHP treatment, the greatest reduction of bacteria and their slowest growth during storage was observed in UV-C/HHP treated samples. The greatest decrease in CA was observed in HHP treated samples. All treatments increased the content of RS, significantly UV-C/HHP with a significant increase in acrylamide content of in fried FCP. The levels of PAHs were below the established limits. The acceptable sensory properties of the samples (raw, boiled and fried) remained stable during the 15-day storage period.Cilj ovog istraživanja bio je ispitati učinak različitih UV-C doza i uvjeta visokoga hidrostatskoga tlaka (VHT) na sigurnost i kvalitetu minimalno procesiranoga krumpira (MPK), te na senzorska svojstva sirovoga i termički obrađenoga, uz praćenje promjena tijekom skladištenja. Nadalje cilj je bio na temelju dobivenih rezultata usporediti utjecaj optimalnoga UV-C i VHT tretmana, kao i njihove kombinacije na svojstva MPK-a. U prvom i drugom dijelu istraživanja MPK je tretiran s 2% otopinom natrijeva askorbata i vakuum pakiran (VP), tretiran UV-C-om (0, 3, 5 i 10 min), te skladišten (23 dana/6 °C). U trećem dijelu MPK su tretirani VHT-om (400 MPa/0, 3, 5 i 10 min) u posudama s otopinom NaAs, te VP i skladišteni. U četvrtom dijelu svi su uzorci pripremljeni kao u prvom i tretirani: UV-C (5 min), VHT (400 MPa/3 min) i kombinacijom UV-C (5 min)/VHT (400 MPa/3 min), te skladišteni. 5- i 10-min UV-C tretmani efikasno su usporili rast ukupnog broja aerobnih mezofilnih bakterija tijekom skladištenja, pozitivno utjecali na boju i miris sirovog SRK-a, dok su termički obrađeni su imali izraženiji miris i okus. Djelovanjem UV-C-a sadržaj klorogenske kiseline (KK) u sirovom MPK-u se smanjio. 5- min UV-C tretman je povećao sadržaj reducirajućih šećera (RS) u sirovom i sadržaj akrilamida u prženom MPK-u, ali je bio ispod predloženog limita. Termičkom obradom smanjio se sadržaj KK i RS. MPK tretiran UV-C-om zadržao je sigurnost, kvalitetu i senzorna svojstva 15 dana. Zbog sličnog antimikrobnoga učinka 5- i 10-min UV-C tretmana i radi uštede energije, 5-min UV-C odabran je za daljnje istraživanje. 10-min VHT tretman značajno je smanjio je broj bakterija. Uzorci tretirani VHT-om 5 i 10 min bili su senzorski slabije ocijenjeni, te su pokazali oštećenja teksture tijekom prženja. 3-min VHT tretman rezultirao je sporijim rastom bakterija tijekom skladištenja i lošijim senzorskim ocjenama kuhanog i prženog MPK-a u donosu na kontrolne uzorke. Za za daljnje ispitivanje odabran je 3-min VHT, ali u VP bez tekućine. Uspoređujući UV-C, VHT i kombinirani UVC/VHT tretman, najveće smanjenje broja bakterija i njihov najsporiji rast tijekom skladištenja uočen je u uzorcima tretiranim UV-C/VHT. Najveće smanjenje sadržaja KK zabilježeno u uzorcima tretiranim VHT-om. Svi tretmani povećali su sadržaj RS, a značajno UV-C/VHT uz značajno povećanje sadržaja akrilamida u prženom MPK-u. Razine PAH-ova su bile ispod utvrđenih granica. Prihvatljiva senzorska svojstva uzoraka (sirovih, kuhanih i prženih) ostala su stabilna tijekom 15 dana skladištenja

Utjecaj UV-C zračenja i visokoga hidrostatskoga tlaka na trajnost i kvalitetu minimalno procesiranoga krumpira (Solanum tuberosum L.)

The aim of this study was to examine the effects of different UV-C doses and high hydrostatic pressure (HHP) conditions on the safety and quality of minimally processed (fresh-cut) potatoes (FCP), and on the sensory properties of raw and thermally treated FCP, while observing the changes during storage. Based on the obtained results, the goal was to compare the effects of optimal UV-C and HHP treatment, as well as their combination, on the properties of FCP. In the first and second part of the research, FCP was treated with a 2% sodium ascorbate solution (SA) and vacuum packed (VP), treated with UV-C (0, 3, 5 and 10 min), and stored (23 days/6 °C). In the third part, FCP was treated with HHP (400 MPa/0, 3, 5 and 10 min) in vessels containing SA solution, VP and stored. In the fourth part, the samples were prepared as in the first part and treated: UV-C (5 min), HHP (400 MPa/3 min) and combined: UV-C (5 min)/HHP (400 MPa/3 min). 5- and 10-min UV-C treatments effectively slowed the growth of aerobic mesophilic bacteria during storage and positively affected the color and odor of raw FCP, while the thermally treated samples had a more pronounced odor and taste. The UV-C decreased the content of chlorogenic acid (CA) in raw FCP. A 5-min UV-C treatment increased the content of reducing sugars (RS) in raw and acrylamide in fried FCP, which was below the suggested limit. Thermal treatment reduced the content of CA and RS. The UV-C treated FCP maintained safety, quality and sensory properties for 15 days. Due to the similar antimicrobial effect of 5- and 10-min UV-C treatments and to save energy, 5-min UV-C was chosen for further investigations. 10-min HHP treatment significantly reduced the bacteria count. The 5- and 10-min treated samples had lower sensory scores, and showed texture damage during frying. The 3-min treatment resulted in significantly slower bacterial growth during storage and lower sensory scores for the boiled and fried FCP compared to control. For further tests, a 3-min HHP was chosen, but in VP without liquid. When comparing UV-C, HHP and UVC/HHP treatment, the greatest reduction of bacteria and their slowest growth during storage was observed in UV-C/HHP treated samples. The greatest decrease in CA was observed in HHP treated samples. All treatments increased the content of RS, significantly UV-C/HHP with a significant increase in acrylamide content of in fried FCP. The levels of PAHs were below the established limits. The acceptable sensory properties of the samples (raw, boiled and fried) remained stable during the 15-day storage period.Cilj ovog istraživanja bio je ispitati učinak različitih UV-C doza i uvjeta visokoga hidrostatskoga tlaka (VHT) na sigurnost i kvalitetu minimalno procesiranoga krumpira (MPK), te na senzorska svojstva sirovoga i termički obrađenoga, uz praćenje promjena tijekom skladištenja. Nadalje cilj je bio na temelju dobivenih rezultata usporediti utjecaj optimalnoga UV-C i VHT tretmana, kao i njihove kombinacije na svojstva MPK-a. U prvom i drugom dijelu istraživanja MPK je tretiran s 2% otopinom natrijeva askorbata i vakuum pakiran (VP), tretiran UV-C-om (0, 3, 5 i 10 min), te skladišten (23 dana/6 °C). U trećem dijelu MPK su tretirani VHT-om (400 MPa/0, 3, 5 i 10 min) u posudama s otopinom NaAs, te VP i skladišteni. U četvrtom dijelu svi su uzorci pripremljeni kao u prvom i tretirani: UV-C (5 min), VHT (400 MPa/3 min) i kombinacijom UV-C (5 min)/VHT (400 MPa/3 min), te skladišteni. 5- i 10-min UV-C tretmani efikasno su usporili rast ukupnog broja aerobnih mezofilnih bakterija tijekom skladištenja, pozitivno utjecali na boju i miris sirovog SRK-a, dok su termički obrađeni su imali izraženiji miris i okus. Djelovanjem UV-C-a sadržaj klorogenske kiseline (KK) u sirovom MPK-u se smanjio. 5- min UV-C tretman je povećao sadržaj reducirajućih šećera (RS) u sirovom i sadržaj akrilamida u prženom MPK-u, ali je bio ispod predloženog limita. Termičkom obradom smanjio se sadržaj KK i RS. MPK tretiran UV-C-om zadržao je sigurnost, kvalitetu i senzorna svojstva 15 dana. Zbog sličnog antimikrobnoga učinka 5- i 10-min UV-C tretmana i radi uštede energije, 5-min UV-C odabran je za daljnje istraživanje. 10-min VHT tretman značajno je smanjio je broj bakterija. Uzorci tretirani VHT-om 5 i 10 min bili su senzorski slabije ocijenjeni, te su pokazali oštećenja teksture tijekom prženja. 3-min VHT tretman rezultirao je sporijim rastom bakterija tijekom skladištenja i lošijim senzorskim ocjenama kuhanog i prženog MPK-a u donosu na kontrolne uzorke. Za za daljnje ispitivanje odabran je 3-min VHT, ali u VP bez tekućine. Uspoređujući UV-C, VHT i kombinirani UVC/VHT tretman, najveće smanjenje broja bakterija i njihov najsporiji rast tijekom skladištenja uočen je u uzorcima tretiranim UV-C/VHT. Najveće smanjenje sadržaja KK zabilježeno u uzorcima tretiranim VHT-om. Svi tretmani povećali su sadržaj RS, a značajno UV-C/VHT uz značajno povećanje sadržaja akrilamida u prženom MPK-u. Razine PAH-ova su bile ispod utvrđenih granica. Prihvatljiva senzorska svojstva uzoraka (sirovih, kuhanih i prženih) ostala su stabilna tijekom 15 dana skladištenja

Effect of UV-C Irradiation, Storage and Subsequent Cooking on Chemical Constituents of Fresh-Cut Potatoes

UV-C irradiation successfully reduces the growth of microorganisms, but it can also affect the content of phenolics and sugars of fresh-cut potatoes (FCP). This could consequently alter antioxidant capacity of FCP or its potential for acrylamide formation. Therefore, this paper investigates the influence of UV-C irradiation on the content of phenolics [chlorogenic acid (CA)] and individual sugars during storage of FCP as well as after cooking. Acrylamide was also monitored in FCP after frying. Potato slices pre-treated with sodium ascorbate solution and vacuum-packaged were UV-C irradiated for 0, 3, 5, and 10 min in order to obtain irradiation doses of 0, 1.62, 2.70, and 5.40 kJ m−2, respectively, stored for 23 days (+6 °C), and subsequently boiled and fried. As the applied dose and storage duration increased, the CA content in raw FCP decreased (it retained for 75.53–88.34%), while the content of sugars as well as acrylamide in fried FCP increased. Although the increase was the most noticeable at the applied dose of 2.70 kJ m−2, the acrylamide content was always below proposed limit. Boiling and frying reduced the content of CA and sugars. In spite of certain alterations, applied doses of irradiation can ensure acceptable product in regard to phenolics and sugars, and acrylamide content particularly

Ružička days : International conference 18th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: chemical analysis and synthesis, chemical and biochemical engineering, food technology and biotechnology, medical chemistry and pharmacy, environmental protection and meeting of young chemists