46 research outputs found
Lemon balm (Melissa officinalis L.) leaves pre-drying by using low energy laser beam
A laboratory laser beam drying method for lemon balm (Melissa officinalis L.) is presented. The aim of this study was to determine the possibility of using lasers as a pre-treatment for drying the lemon balm leaves and also to determine the variation of water content during the treatment. Leaves were illuminated from one side during a period of 180 s with 100 mW and 200 mW lasers. Both sources of coherent light were in the red part of the visible spectrum with wavelengths of 650 nm. Freshly harvested lemon balm leaves with 75.64% of water content were used for the analysis. Low-energy laser beam treatment for a period of 180 s resulted in the reduction of water content of 0.307% for 100 mW laser treatment and 0.31% for the 200 mW laser treatment. Amounts of energy emitted by low energy lasers are relatively small. Therefore, lasers thermal influence is negligible so it can be concluded that laser activity on lemon balm leaves is based solely on biostimulation. The proposed method allows effective reduction of water content without causing damage to the plant material. For practical application, dryers with integrated laser diode network were proposed. Low energy coherent radiation treatment represents an inexpensive and environmentally safe method that does not pollute the environment. This method also provides close control of the process, and in spite of the greater cost of energy, the overall increase in drying efficiency and throughput can bring about significant economic savings.</p
Colour stability and antioxidant activity of some berry extracts
The colour stability of the blackberry, mulberry and blueberry extracts by monitoring the changes in colour parameters and remaining absorbance as a result of increased temperature and heating time were examined. The knowledge of colour stability is important for optimization of production and storage of coloured food products. The aim of present study was also to determine and compare the total phenols content and antioxidant activity of these dark coloured berry fruits. The results showed that highest total phenols content was determined in blueberry extracts (3198.50 mg kg-1). Extracts were analyzed for antioxidant activity by the ABTS and DPPH methods. The heating time and temperature affected the colour stability of the berry fruit extracts. The maximum colour stability was determined for mulberry extract
Influence of Fruit Thinning and Summer Pruning on the Yield and Fruit Quality of Peach Cultivar \u27Royal Gem\u27
Peach is one of the most important fruit species for human consumption. In the peach cultivation many pomotechnical treatments are conducted and some of the most interesting are summer pruning and fruit thinning. By implementation of mentioned pomotechnical treatments higher fruit quality can be achieved which is nowadays very important for the market fruit value. In this research the influence of summer pruning and fruit thinning in different combinations on the pomological characteristics and physico-chemical properties of peach fruit cultivar ‘Royal Gem’ was studied. Implemented pomotechnical treatments differently affected the studied properties. The highest yield was determined in control (7.23 kg tree-1) while the lowest (4.38 kg tree-1) in treatment 2 (fruit thinning without summer pruning). Fruit thinning and summer pruning significantly influenced on the increase of average fruit weight, fruit firmness and fruit diameter. The lowest fruit weight (75.74 g) was determined in control while the highest fruit weight (92.93 g) was determined in treatment 3 (summer pruning without fruit thinning). The highest fruit diameter (57.69 mm) was also determined in treatment 3 while the lowest in control (52.59 mm). The highest fruit firmness (4.14 kg/cm2) was in treatment 1. For chemical quality properties no significant differences have been determined due to the implemented pomotechnical treatments. The pomotechnical treatments conducted in this research showed to be effective for improving the fruit quality while the best results were achieved by treatment of fruit thinning
Nutritional Composition of Different Varieties of Apple Purees Sweetened with Green and White Stevia Powder
The aim of this study was to analyze the chemical composition of apple purees of four different apple varieties: ‘Golden Delicious’, ‘Idared’, ‘Jonagold’ and ‘Cripps Pink’, in the fresh state (FP) and after thermal treatment by process of pasteurization with added green (PG) or white stevia powder (PW) derived from the leaves of the stevia plant. Also, to determine whether there is a significant influence of sweetening with stevia on the change of analyzed nutritional parameters of apple purees based on the results. Significant increase of dry matter content in PG and PW samples of apple purees was determined for approximately 10%, and also for total soluble solid content for 1%. High increase of natural invert content, for approximately five times higher, and some lower increase of total invert content of analyzed purees was determined in PG and PW samples in comparison with the FP samples. Total acid content and pH value did not show any significant change during the process of pasteurization and sweetening with stevia. The pasteurization significantly influenced the slight vitamin C reduction as well as the high reduction of total phenols in PG and PW samples. Based on the obtained results it can be concluded that the thermal processing by pasteurization significantly affects the degradation of high antioxidant activity compounds. Adding a green and white stevia powder significantly influenced the alterations of some nutritional components analyzed in apple purees: the dry matter content, soluble solids, and natural invert content (sugar glucose). It is important to emphasize, that the main effect of green and white stevia powder was the increase of natural invert content i.e. content of glucose and fructose, thereby increasing the sweetness of product, without increasing the content of “harmful” sugars e.g. sucrose
Influence of Fruit Thinning and Summer Pruning on the Yield and Fruit Quality of Peach Cultivar \u27Royal Gem\u27
Peach is one of the most important fruit species for human consumption. In the peach cultivation many pomotechnical treatments are conducted and some of the most interesting are summer pruning and fruit thinning. By implementation of mentioned pomotechnical treatments higher fruit quality can be achieved which is nowadays very important for the market fruit value. In this research the influence of summer pruning and fruit thinning in different combinations on the pomological characteristics and physico-chemical properties of peach fruit cultivar ‘Royal Gem’ was studied. Implemented pomotechnical treatments differently affected the studied properties. The highest yield was determined in control (7.23 kg tree-1) while the lowest (4.38 kg tree-1) in treatment 2 (fruit thinning without summer pruning). Fruit thinning and summer pruning significantly influenced on the increase of average fruit weight, fruit firmness and fruit diameter. The lowest fruit weight (75.74 g) was determined in control while the highest fruit weight (92.93 g) was determined in treatment 3 (summer pruning without fruit thinning). The highest fruit diameter (57.69 mm) was also determined in treatment 3 while the lowest in control (52.59 mm). The highest fruit firmness (4.14 kg/cm2) was in treatment 1. For chemical quality properties no significant differences have been determined due to the implemented pomotechnical treatments. The pomotechnical treatments conducted in this research showed to be effective for improving the fruit quality while the best results were achieved by treatment of fruit thinning
Utjecaj različitih predtretmana na sadržaj biološki aktivnih spojeva u plodu sušenih šljiva
Plum (Prunus domestica L.) is mostly represented on the European market as fresh or industrially processed as dried fruit. The plum drying process is usually carried out at higher temperatures between 85 and 90 °C, which can result with loss of bioactive compounds, sensory attributes, texture, taste and aroma. Therefore, the aim of this study was to examine the efficiency of applying different pre-treatments in combination with a lower drying temperature (42 °C) in order to obtain a high quality product and the highest retention of bioactive compounds (total phenols, total hydroxycinnamic acids and total flavonols). Three plum cultivars: cv ‘Hauszwetschge Schuffer’, cv ‘President’ and cv \u27Topend plus\u27 were treated with 11 different pre-treatments: abrasion in duration of 5, 10 and 15 minutes; submersion in KOH solution in concentration of 0,5, 1,0 and 1,5% at two temperatures of 22 °C and 60 °C in duration of 1 minute, and submersion of fruits in distilled water at two temperatures (22 and 60 °C) in duration of 1 minute. The highest retention of bioactive compounds (total phenols, total hydroxycinnamic acids and total flavonols) was obtained in the dried fruits of all plum cultivars treated by chemical and thermal pre-treatment while the lowest values were determined in fruits pre-treated with abrasion.Šljiva (Prunus domestica L.) uglavnom je prisutna na tržištu EU kao svježa ili industrijski prerađena kao sušeni plod. Tehnologija sušenja šljive uglavnom se provodi se na visokim temperaturama između 85 i 90 °C koji mogu rezultirati gubitkom bioaktivnih spojeva, senzornih svojstava, teksture, okusa i arome. Stoga je cilj ovog rada bio istražiti učinkovitost primjenjenih različitih predtretmana u kombinaciji s nižom temperaturom sušenja (42 °C) radi dobivanja visoko-kvalitetnog proizvoda, koji će imati visok stupanj zadržavanja biološki aktivnih spojeva (ukupnih fenola, ukupnih hidroksicimetnih kiselina i ukupnih flavonola). Tri sorte šljive ‘Hauszwetschge Schuffer’, ‘President’ i ‘Topend plus’ tretirane su s 11 različitih predtretmana: abrazija u trajanju od 5, 10 i 15 minuta, potapanje u otopinu KOH u koncentracijama od 0,5, 1,0 i 1,5% na temperaturi od 22 °C i 60 °C u trajanju od 1 minute te sa destiliranom vodom na dvije temperature (22 i 60 °C), također u trajanju od 1 minute. Najviši sadržaj bioaktivnih spojeva (ukupni fenoli, ukupne hidroksicimetne kiseline i ukupni flavonoli) utvrđeni su u sušenih plodova svih sorti tretiranih s kemijskim i termičkim predtretmanima, dok su najniže vrijednosti spomenutih bioaktivnih spojeva utvrđeni u plodovima predtretiranih abrazijom
Functional value and nutritional potential of plantain products (Arbutus unedo L.)
Cilj ovog istraživanja bio je utvrditi fizikalno-kemijska svojstva, sadržaj bioaktivnih spojeva i nutritivni potencijal dvaju proizvoda planike: džema i vodene infuzije listova. Način pripreme džema varira postupkom pasiranja: nepasirani (NP1) i pasirani džem (P2). Džem tretmana NP1 imao je značajno viši sadržaj ukupne i topljive suhe tvari te višu pH- vrijednost u usporedbi s P2. Također, tretman pasiranja utjecao je i na promjenu boje gotovog proizvoda prilikom čega je za džem P2 utvrđeno svjetlije crveno, a džem NP1 tamnije crveno obojenje. Postupak pasiranja pridonio je povećanju sadržaja pojedinih bioaktivnih spojeva u P 2, p rilikom č ega j e u d žemu t retmana P 2 utvrđen 17% viši sadržaj vitamina C, značajno viši sadržaj polifenolnih spojeva kao i viši antioksidacijski kapacitet u usporedbi s NP1. No, oko 3 puta viši sadržaj β-karotena utvrđen je u NP1 džemu. Također, iz analize vodene infuzije listova vidljiv je visok sadržaj bioaktivnih spojeva, a posebice ukupnih fenola (715,79 mg GAE/100 g svježe tvari). Temeljem svega, može se zaključiti kako oba proizvoda obične planike pokazuju visok nutritivni potencijal i značajnu funkcionalnu vrijednost, a time predstavljaju zdravstveno vrijedne proizvode široke mogućnosti upotrebe.The aim of this research was to determine the physical and chemical parameters, content of bioactive compounds and nutritional potential of two strawberry tree products: jam and leaves water infusion. The method of jam preparation was varied by straining/mashing: non-strained (NP1) and strained (P2) jam samples. Jam prepared by NP1 treatment had a significantly higher total dry matter content, total soluble solids and pH-value compared to the P2 jam. Also, straining/mashing treatment affected the color change of final product, which in brighter red color was determined for P2 jam, while darker red coloration described NP1 jam. Straining treatment contributed to the increase of the bioactive compounds content in P2, where a 17% higher vitamin C content was determined as well as a higher total polyphenol content and a higher antioxidant capacity compared to the NP1 jam. However, a three-fold higher β-carotene content was determined in NP1 jam. From chemical analysis of leaves water infusion, a high content of bioactive compounds, especially total phenols (715,79 mg GAE/100 g fresh weight), is noticeable. Based on all above-mentioned, it can be concluded that both strawberry tree products show a high nutritional potential and a significant functional value, thus representing health-valuable products with a wide range of uses
INNOVATIONS IN TRANSPORTATION OF MEAT AND MEAT PRODUCTS
Poznato je da tijekom prijevoza ili skladištenja mesa i mesnih prerađevina može doći do bioloških, kemijskih, mehaničkih ili organoleptičkih promjena, tj. da se kakvoća navedenih roba smanjuje. U transportno distributivnom lancu svaka je karika izuzetno važna. Stoga se skladištenje, čuvanje i transport mesa i mesnih prerađevina mora odvijati uz stalni veterinarski nadzor. Osim navedenog, transportna sredstva trebaju udovoljavati svim zdravstveno-higijenskim i tehničkim uvjetima. U Hrvatskoj je najviše zastupljen cestovni prijevoz poljoprivredno prehrambenih proizvoda, pa tako i mesa i mesnih prerađevina. Dosadašnji transport svježeg kao i zamrznutog mesa od klaonice do tržišta odvija se u kamionima sa hladioničkim komorama, a cijeli je sustav transporta uključen u tzv. „hladni lanac“. Temeljem prikupljenih podataka i njihove analize, cilj ovog rada je prikazati složenost procesa u pripremi, transportu i skladištenju mesa i mesnih prerađevina. Prednosti efikasnog, dobro održavanog hladnog lanca su: smanjenje troškova; očuvanje kakvoće robe (proizvoda) i smanjenje gubitaka - rasipanje i povrat robe. Transportni proces uključuje niz nepredvidivih čimbenika koji utječu na promjene temperature unutar hladioničke komore. Međutim, praćenjem hladnog lanca cilj je osigurati kakvoću i sigurnost proizvoda kroz cijeli distributivni lanac. Iz tog razloga, pokrenut je istraživački projekt „inteligentni kontejner“ i razvijen je kontejner koji omogućava, kroz kombinaciju tehnologije i računalnih programskih paketa, praćenje kakvoće procesa distribucije za lako pokvarljivu robu uz optimizaciju logističkih procesa s ciljem smanjenja gubitaka u transportu i skladištenju.It is well known that during the transport and storage of meat and meat products, biological, chemical, mechanical or organoleptic changes may occur, i.e. the quality of products decreases. In the transport supply chain, each link is extremely important. Therefore, the storage, preservation and transportation of meat and meat products must take place under the constant supervision. In addition, transport vehicles should comply with food safety, hygiene and technical requirements. In Croatia, road transport is the predominant mode of transport of agricultural food products, including meat and meat products. Former transport of fresh and frozen meat from the slaughterhouse to the market takes place in trucks with refrigeration chambers, and the entire transportation system is included in the so-called “Cold chain”. Based on the collected data and their analysis, the aim of this paper is to show the complexity of the process of the preparation, transport and storage of meat and meat products. The benefits of an efficient, well maintained cold chain are: cost reduction; keeping quality of the goods (products) and loss reduction - waste and return of goods. The transport process involves a series of unpredictable factors that influence changes in temperature within the refrigeration chamber. However, objective of cold chain monitoring is to ensure the quality and safety of products throughout the distribution chain. For this reason, the research project „intelligent container“ developed a container that enables, through combination of technology and computer software packages, quality monitoring of distribution processes to optimize logistics processes in order to minimize losses in transport and storage
Application of physical pre-treatment of abrasion in the plum drying process
Voštana prevlaka površine kožice ploda šljive ključna je prepreka gubitku vode prilikom postupka sušenja te ju je nužno ukloniti. Cilj ovog rada bio je istražiti utjecaj primjene različitih predtretmana, kemijskog (primjenom lužine), fizikalnog (primjenom abrazije) i toplinskog (ugrijanom destiliranom vodom) na vrijeme sušenja plodova šljive sorte \u27President\u27. Također, varirani su i ključni parametri svakog pojedinog predtretmana poput temperature otopine prilikom toplinskog (22 i 60 °C), koncentracije (0,5, 1 i 1,5% v/v) i temperature (22 i 60 °C) lužine (KOH) kod kemijskog i vremenskog perioda abrazije (5, 10 i 15 min) kod fizikalnog. Prema dobivenim rezultatima, kemijski predtretman lužinom koncentracije 1 i 1,5% temperature 60 °C bio je najučinkovitiji, vrijeme sušenja iznosilo je svega 27 sati, adok je samo 2 sata dulje (29 h) trajalo sušenje plodova predtretiranih abrazijom u vremenu od 15 min. Temeljem svega, može se zaključiti kako je fizikalni predtretman abrazijom izrazito učinkovit u uklanjanju voštane prevlake, time i u skraćivanju vremena sušenja plodova šljive, a isto tako treba naglasiti kako primjenom abrazivnog predtretmana značajno utječemo na smanjenje onečišćenja okoliša, ali i na zdravlje ljudi, s obzirom da nema ostataka kemijskih sredstava koja nakon primjene treba adekvatno zbrinuti, jer potencijalno mogu negativno utjecati na čovjeka i okoliš.Wax coating from the surface of the plum fruit skin is a key barrier to water loss during the drying process and it is necessary to remove it. Therefore, the aim of this study was to examine the impact of the application of different pre-treatments, i.e. chemical (using alkali solution), physical (using abrasion) and thermal (heated distilled water) on the drying time of plum fruits cv. \u27President\u27. Also, the key factors of each pre-treatment varied, such as the temperature of the solution in the thermal pre treatment (22 and 60 °C), the concentration (0.5, 1 and 1.5% v/v) and the temperature (22 and 60 °C) of the alkali solution (KOH) in the chemical and time duration of abrasion (5, 10 and 15 min) in the physical pretreatment, while the influence of each pre-treatment was researched. According to the obtained results, chemical pre-treatment with alkali solution concentration of 1 and 1.5% temperature of 60 °C was most effective in shortening the drying time of plums, lasted only 27 hours, while only 2 hours longer (29 h) lasted the drying of plums pre-treated by abrasion of 15 min. Based on all mentioned, it can be concluded that the physical pre-treatment by abrasion is extremely effective in removing the wax coating thus affecting shortening the drying time of plum fruits, and it should be emphasized that the application of abrasive pretreatment significantly affects the reduction of environmental pollution, but also human health, given that there are no chemical residues that after application should be adequately disposed of, which can affect humans and environment
Procjena nutritivnog potencijala i sadržaj specijaliziranih metabolita nekih vrsta agruma
The aim of this study was to assess the nutritional composition of fruits of some citrus species (sweet orange, grapefruit, clementine and kumquat) and to determine their basic physicochemical parameters, bioactive compounds content, and antioxidant capacity. According to the analyzed data, kumquat fruits had the highest dry matter content (18.71%) and total acid content (3.08%), while the highest values of total soluble solids (13.41%), pH value (3.92), vitamin C (53.69 mg/100 g FW), total phenols (162 mg GAE/100 g FW), β-carotene (1053.17 µg/100 g FW), and antioxidant capacity (1.70 mmol TE/kg) were determined in clementine fruits. Considering the nutritional composition of citrus fruits, it can be concluded that they are a rich source of various bioactive compounds, especially vitamin C, carotenoids, and polyphenols, and are characterized by their high antioxidant capacity, which is important for health. Moreover, the cultivation of citrus fruits is an important factor in the Croatian economy, which should be promoted in the future, and the potential of the southern part of Croatia for the cultivation of these citrus fruits should be exploited to the maximum.Cilj ovog istraživanja bio je valorizirati nutritivni sastav plodova određenih vrsta citrusa: slatke naranče, grejpa, klementine i kumkvata, analizirajući njihova osnovna fizikalno-kemijska svojstva, sadržaj bioaktivnih spojeva i antioksidacijski kapacitet. Prema analiziranim podacima, plodovi kumkvata imali su najviše vrijednosti ukupne suhe tvari (18,71%), ukupnih kiselina (3,08%), dok su istodobno u plodovima klementine utvrđene najviše vrijednosti topljive suhe tvari (13,41%), pH vrijednosti (3,92), vitamina C (53,69 mg/100 g FW), ukupnih fenola (162 mg GAE/100 g FW), β-karotena (1053,17 µg/100 g FW) i antioksidacijskog kapaciteta (1,70 mmol TE/L.) Temeljem analiziranih parametara nutritivnog sastava plodova različitih vrsta citrusa može se zaključiti kako su agrumi bogat izvor različitih bioaktivnih spojeva, posebice vitamina C, karotenoida i polifenola, pa ih stoga karakterizira i visok antioksidacijski kapacitet, a što je od iznimne važnosti i za zdravlje ljudi. Štoviše, uzgoj agruma važan je čimbenik u hrvatskom gospodarstvu, koji bi trebalo dodatno promovirati, dok potencijal južnog dijela Hrvatske za uzgojem ovih agruma treba maksimalno iskoristiti