Sirvi Autor "Kruma, Z." järgi
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Kirje Changes in the nutritional value of breakfast cereals containing germinated spring grain flakes during storage(2018) Kruma, Z.; Galoburda, R.; Tomsone, L.; Gramatina, I.; Senhofa, S.; Straumite, E.; Klava, D.; Kince, T.; Cinkmanis, I.; Zagorska, J.; Kunkulberga, D.Th e aim of current research was to assess the nutritional value of breakfast cereals containing germinated spring grain flakes and its changes after 6 month storage. Three types of breakfast cereals were prepared and packaged in two types of Standup pouches – Pap50g/Alu7/Pe60 (AL), Pap40g/PELD20/PE40 (PE). For the accelerated shelf life test the samples were stored at 35 ± 2 °C and dietary fibre, protein, fat, B - group vitamins, sugars, total phenol content and DPPH, ABTS+ radical scavenging activity were dete rmined. Developed breakfast cereals have high nutritional value and all are high in fibre and thiamine. Additionally, sample S2 is source of protein, riboflavin, niacin, and S3 – is source of riboflavin and high in niacin. Comparing total phenolic content and antioxidant capacity of tested samples S3 showed the highest values. Storage and selected packaging influenced stability of nutrients, and for S1 and S2 AL showed bett er results whereas for S3 – PE.Kirje Comparison of phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes(2018) Zarins, R.; Kruma, Z.; Tomsone, L.; Kampuse, S.; Skrabule, I.; Konosonoka, I.H.Potatoes (Solanum tuberosum L.) contain a wide range of compounds with health benefits, and different techniques have been developed for the determination of these compounds. Freeze-drying is a common method for the preservation and preparation of samples for the analyses of bioactive compounds, but it is well known that drying influences the composition of food products. The aim of the current study was to compare phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes. In the experiment 11 cultivar potatoes grown in experimental fields of the Institute of Agricultural Resources and Economics in 2016 were analysed. Potatoes were freeze-dried. Homogenized fresh and freeze-dried samples were extracted with an ethanol/water (80/20 w/w) solution. Total phenolic content (TPC) was determined using the Folin-Ciocalteu method, and the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH˙) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The highest TPC and radical scavenging activity were determined in cultivars ‘Peru Purple’ and ‘Blue Congo’ potatoes. Freeze-drying influenced all the tested parameters but more significantly the TPC, and for certain cultivars a reduction of more than 30% was observed. A strong correlation between TPC, DPPH and ABTS in fresh and freeze-dried samples was observed, r = 0.81, r=0.93, r = 0.92, respectively. It could be concluded that the effect of freeze-drying on TPC and antioxidant activity is cultivar dependent.Kirje Effects of processing conditions on physical parameters of triticale flakes(2018) Kince, T.; Straumite, E.; Klava, D.; Kruma, Z.; Abelniece, K.; Balgalve, A.Consumer interest in breakfast cereal flakes has increased during the last few years. Various technologies, used to produce flakes, significantly influence their quality parameters and shelf - life stab ility. The main purpose of the present research was to investigate how different processing methods affect the physical parameters of triticale flakes. For obtaining the flakes, cleaned whole triticale grains were treated using the following technologies: dry processing (hot air), steam processing and soaking with subsequent steaming. For preparing the flakes different kilning methods and traditional flaking rolls were used. Traditionally made rolled and dried whole grain triticale flakes were analysed as a control sample. Using standard methods, the flakes’ moisture content, water activity, microstructure, swelling capacity and colour changes were analysed. The gap settings of flake rollers do not influence significantly ( P < 0.05) changes of starch during processing. However, the starch granules were fully transformed into sugars in the flake samples with greater thickness. Non - significant ( P < 0.05) steaming and hot air drying (toasting) conditions’ effects were observed on the changes of the starch granules during processing. Strong correlation was determined during the analysis of water activity and moisture content. The moisture content of the ready - to - eat flakes varied from 2.54% to 10.66%, and the water activity value was from 0.108 to 0.494. Compared with traditionally processed flakes (control sample) the colour of the flakes prepared using other technologies changed significantly, the E values varied from 9.587 to 18.554. The colour of the soaked - steamed - rolled - hot air dried samples was similar but those significantly differed from the colour of soaked - dried - rolled - hot air dried flake samples. The soaked - dried - rolled - hot air dried flakes were darker compared with other analysed flake samples.Kirje Influence of technological parameters on chemical composition of triticale flakes(2018) Kruma, Z.; Straumite, E.; Kince, T.; Klava, D.; Abelniece, K.; Balgalve, A.Triticale is hybrid crop developed by crossing wheat ( Triticum ) and rye ( Secale ) and in last years it become more popular for food applications, including flake production. Different approaches are developed to improve flakes technology by applying different cooking, rolling, toasting parameters resulting in high quality products. All these technologies influence also nutrition quality of product due to the diffe rent stability of these compounds during mechanical and thermal treatment. The aim of current experiment was to investigate the influence of technological parameters on chemical composition of triticale flakes. In current experiment triticale grains and tr iticale flakes obtained by different technologies was tested. For evaluation of the influence of technological parameters, different flaking and rolling parameters were tested. For all samples were determined composition of basic nutrients (fats, proteins, fibres, sugars, ash), minerals (Ca, Mg, K, Zn, P), vitamins, total phenolics and antioxidant activity. Triticale has high nutritional quality, containing significant amounts of protein, fibres, vitamins and minerals. Technological processes significantly influence cereals composition, but it depends on parameters tested. Control sample showed lower results and hierarchical cluster analyses showed that samples 1/3/1, 2/1/2/1, 2/1/3/1, 2/1/4/1 are similar in composition of bioactive compounds. Results showed that for selection of the best method for flaking physical and/or sensory properties should be taken in account.Kirje Optimisation of biologically active compounds ultrasound assisted extraction from potatoes using response surface methodology(2018) Zarins, R.; Kruma, Z.; Skrabule, I.Potato ( Solanum tuberosum L.) is source of p henolic compounds and from plant matrixes can be extracted by several methods. In recent years ultrasound assisted extraction has become more popular due to its efficiency for recovery of phenolic compounds and antioxidants and response surface methodology is an effective tool for optimisation of extraction procedure by evaluating different variables and their interaction. The aim of the current research was to optimize ultrasound assisted extraction of biologically active compounds from potatoes by respons e surface methodology. For experiment purple - flesh potato variety ‘Blue Congo’ was selected. Control sample was extracted by stirring for 1 hour. Box - Behnken design was used for optimization of extraction conditions from fresh potatoes and as variables wer e selected: ethanol concentration (% v/v), hydrochloric acid concentration (molarity) and time (min). For extracts as responses total phenolic, total flavonoid, total anthocyanin content and antioxidant activity (DPPH, ABTS+ scavenging activity) were deter mined using a spectrophotometric methods. Significant models were obtained for antocyanins, total phenols and DPPH radical scavenging activity. Optimisation of extraction showed that for maximising all responses optimal HCl concentration is 2.5M, ethanol c oncentration 79.4% and extraction time 60 minutes, resulting in following responses: 57.41 mg 100 g - 1 of anthocyanins, 238.52 mg 100 g - 1 of TPC, 24.58 mM TE 100 g - 1 of DPPH scavenging activity and 12.99 mM TE 100 g - 1 of ABTS scavenging activity. Convention al extraction method showed significantly lower results. It could be concluded that ultrasound assisted extraction is effective method for recovery of phenolic compounds and solvents and extraction time is significant parameter influencing efficiency.Kirje Phenolic and volatile compound composition influence to specialty coffee cup quality(2019) Laukaleja, I.; Kruma, Z.With increasing specialty coffee consumption, more attention is focused not only on the cup quality (sensory quality) of the coffee beverage but also about the impact of coffee on health. The beneficial effects of coffee on human health are mainly based on a wide range of biologically active components, including phenolic compounds. The aim of the study was to evaluate the influence of phenolic and volatile compound composition to specialty coffee cup quality. Seven specialty coffees from two Latvian roasteries were selected and analysed. Total phenolic and flavanoid content and radical scavenging activity by DPPH and ABTS assay were determined spectrophotometrically. Sensory evaluation (cup quality) was performed by trained panellist team using the SCAA protocols cupping specialty coffee. Volatile compounds were extracted by SPME and analysed by Gas Chromatography-Mass Spectrometry (GC–MS). Coffee final cup quality score ranged in amplitude of 83–90.25 points. HON_2 with dry fruits and melon characteristics has shown the highest final cup quality score. Almost detected volatile compounds in KEN_1 is associated with positive specialty coffee characteristics. In ETH_1 coffee with the final cup quality score 88.25 was detected highest floral, fruity compounds and highest coffee– like roasted notes. The highest total phenolic content and DPPH, ABTS•+˙ value showed Roastery_1 coffee samples (HON_1; KEN_1; COL_1) and the lowest values Roastery_2 coffee samples (HON_2; ETH_1; HON_3; SAL_1).The results indicate that the roastery specific roasting process parameters could influence not only volatile compounds profile and cup quality but also the total and individual phenolic compound content.