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Anthocyanin content in Latvian cranberries dried in convective and microwave vacuum driers
2011
Ruse, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rakcejeva, T., Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dukalska, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The current research focuses on the study of anthocyanin content changes in Latvia wild growing as well as cultivated cranberries during convective and microwave vacuum drying. The research was accomplished on fresh Latvian wild and cultivated cranberries. The berries before drying in a convective drier were pre-treated using perforating, steam-blanching and halving; berries dried in microwave vacuum drier – using steam-blanching and halving; part of berries was dried in microwave vacuum drier without pre-treatment (whole berries). For air drying experiments, a convective dryer “Memmert” (Model 100-800) was used. For drying experiments in microwave vacuum a dryer „Musson-1” was used. Anthocyanin was determined by means of spectrophotometric method. Data are expressed as mean ± standard deviation; variance analysis, homogeneity were used for the evaluation of changes of anthocyanin in cranberries during drying depending on pre-treatment methods. The initial content of anthocyanin among wild and cultivated fresh cranberries was differing: very similar anthocyanin content was detected in cranberry cultivars ‘Pilgrim’ and ‘Early Black’, it was on average three times higher comparing to wild fresh cranberries. However, the lowest anthocyanin content was detected in wild fresh cranberries – 306.81 ± 4.19 mg 100gE-1 (in dry matter). With the probability of 95%, detected by means of the analysis of variance, it may be presumed, that pre-treatment method of cranberries influenced anthocyanin changes during convective and microwave vacuum drying (p=0.001, is less than =0.05). Halving is advisable as a pre-treatment method for berries processing in a convective or microwave drier, because decrease in anthocyanin content is smaller.
Show more [+] Less [-]Stinging nettle − the source of biologically active compounds as sustainable daily diet supplement
2014
Zeipina, S., Latvia Univ. of Agriculture, Jelgava (Latvia);Pure Horticultural Research Centre, Pure parish, Tukuma municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lepse, L., Pure Horticultural Research Station, Pure parish, Tukuma municipality (Latvia)
Environmental conditions and climate change on a global scale affects the overall agriculture and food supply. Consumers demand for vegetables with high nutritional value is increasing. Consumers more and more are thinking about a healthy and balanced diet, but it is not easy to provide year-round fresh vegetables. Nettle (Urtica) leaves traditionally are used in early spring as a leafy vegetable in salads and soups. Young leaves before flowering are used for human consumption. Nettle contains a lot of vitamins and biologically active compounds. The research aim was to evaluate different stinging nettle clones, which grow in Pūre village (Tukuma district, Latvia). Samples were collected, when shoots were 10 – 15 cm long. Content of chlorophyll, carotenoids and anthocyanins in five nettle clones leaves were analysed. Biochemical analysis was done in Latvia University of Agriculture, Institute of Soil and Plant Science laboratory. Differences were observed between all clones. Significant difference between genotypes was observed in anthocyanins content, but not in chlorophylls and carotenoids content. Higher anthocyanins content was observed in samples, which grow in places with low nitrogen and phosphorus content. Content of biochemical compounds can influence some metal ions, environmental and other factors.
Show more [+] Less [-]Stinging nettle - the source of biologically active compounds as sustainable daily diet supplement
2014
Zeipina, S., Latvia Univ. of Agriculture, Jelgava (Latvia);Pure Horticultural Research Centre, Pure parish, Tukuma municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lepse, L., Pure Horticultural Research Station, Pure parish, Tukuma municipality (Latvia)
Environmental conditions and climate change on a global scale affects the overall agriculture and food supply. Consumers demand for vegetables with high nutritional value is increasing. Consumers more and more are thinking about a healthy and balanced diet, but it is not easy to provide year-round fresh vegetables. Nettle (Urtica) leaves traditionally are used in early spring as a leafy vegetable in salads and soups. Young leaves before flowering are used for human consumption. Nettle contains a lot of vitamins and biologically active compounds. The research aim was to evaluate different stinging nettle clones, which grow in Pūre village (Tukuma district, Latvia). Samples were collected, when shoots were 10 – 15 cm long. Content of chlorophyll, carotenoids and anthocyanins in five nettle clones leaves were analysed. Biochemical analysis was done in Latvia University of Agriculture, Institute of Soil and Plant Science laboratory. Differences were observed between all clones. Significant difference between genotypes was observed in anthocyanins content, but not in chlorophylls and carotenoids content. Higher anthocyanins content was observed in samples, which grow in places with low nitrogen and phosphorus content. Content of biochemical compounds can influence some metal ions, environmental and other factors.
Show more [+] Less [-]Yield maturity parameters of hybrid grapevine (Vitis sp.) cultivar ‘Zilga’
2014
Raetsep, R., Estonian Univ. of Life Sciences, Tartu (Estonia) | Karp, K., Estonian Univ. of Life Sciences, Tartu (Estonia) | Vool, E., Estonian Univ. of Life Sciences, Tartu (Estonia)
The number of grape (Vitis sp.) cultivars is increasing every year, the focus point of recent grapevine studies are heading to producing high quality fruits for producing quality wine. A field trial with cultivar ‘Zilga’ was established in 2007 at the Estonian University of Life Sciences and in 2010 in a greenhouse. ‘Zilga’ is one of the well adopted cultivars in Estonia, which has been used mostly for producing wine and grown in open field conditions. The aim of the present experiment was to find out the yield maturity parameters of cultivar ‘Zilga’ for red wine in Estonian conditions. Data was collected from the year 2011 to 2013. The bunch weight and °Brix were determined from fresh materials, but all the other biochemical parameters were determined from frozen (-20 °C) grapes. The recommended content (20 °Brix) of soluble solids was not obtained in open field conditions, but reached to 24.1 °Brix in greenhouse conditions in 2013. Titratable acids content was higher than recommended values, ranging from 1.4 to 1.6 mg 100 gE-1 in open field and showing the lowest content (1.2 mg 100 gE-1) in greenhouse conditions. Maturity index values ranged from 117 to 224, and the optimum was reached in two years from three. The highest total phenolics content, 293 mg 100 gE-1 was obtained in 2011, while anthocyanin content was significantly increased in 2013.
Show more [+] Less [-]The effect of vacuum cooking on enteral food made from fresh and semi-finished ingredients
2017
Ozola, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kampuse, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
Enteral feeding also known as enteral nutrition is nutrient delivery into the stomach. Products for enteral nutrition are a specific group of products designed to provide nutrients to the human body in case of various diseases and after surgery, when the daily intake of the product is affected. Today market offers special dietetic products, which are supplemented with synthetic vitamins and minerals, which bioavailability in the body is lower than that of natural organic complexes. Therefore it is important to develop special dietetic products from natural raw materials. The aim of this study was to evaluate the effect of vacuum cooking on the content of bioactive compounds, soluble solids, pH and shelf life of enteral food made from fresh and semi-finished (heated) fruit and vegetable juices. For this research enteral food was made using fresh or semi-finished fruit and vegetable juices. Products were vacuum cooked in 0.02 MPa pressure, with boiling point 67 °C, and 0.06 MPa pressure at 79 °C, withstander for 15 min. All samples were stored at room temperature and tested for their content of vitamin C, total carotenoids, anthocyanins, total phenols and antioxidant activity and microbiological safety, as control untreated enteral food samples were used. The obtained data showed that samples made from semi-finished juices have higher contents of vitamin C and total carotenoids and anthocyanins than samples prepared from fresh juices, but this wasn’t observed with content of total phenols and antiradical scavenging activity (DPPH), where the type of ingredients used for sample preparation had no significant effect.
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