The influence of drying method to the changes of bioactive compounds in lingonberry by-products

ArticleThe aim of this research was to evaluate the effect of different drying methods on industrially obtained lingonberry pulp juice by - products. For investigations, by - product was dried using hot air dryer (at temperatures 80 °C , 60 °C and 40 °C ), microwave - vacuum dryer and freeze - dryer. The freshly defrosted by - product was used as control. All samples were analysed on the basis of their moisture content, colourimetric attributes (CIE L*a*b* colour system), content of vitamin C (iodometric method), content of total carotenes (TC), total phenol content (TPC), total anthocyanin content (TA) and antiradical activity (DPPH, ABTS + ). The obtained data on content of vitamin C showed a 10% decrease between control and sample dried in hot air at 80 °C . Similar changes were noticed with total anthocyanin content, the lowest amount was also foun in this sample ( 306.72 ± 18.32 mg 100 g - 1 DW). Total carotenes content was higher in freeze - dried sample (5.61 ± 0.16 mg 100 g - 1 DW) which was very close to control sample. A significant loss of total phenol content was noticed after drying, up to 80%, similar ten dencies were noticed with changes of antiradical activity. After evaluating the obtained data, the use of hot air dryer at 80 °C temperature resulted in the lowest amount of vitamin C and anthocyanins in lingonberry by - products, which makes this method unsuitable for drying by - products of these berries. However, vacuum assisted microwave drying and freeze drying showed less damaging impact on dried material

Effect of drying technologies on bioactive compounds maintenance in pumpkin by-products

ArticleDuring the pumpkin processing large amounts of waste material as a combination of pumpkin peel, seeds and the flesh between seeds has produced. Therefore it is important to investigate the possibilities for using the pumpkin residues. The aim of this resea rch was to investigate the effect of different drying technologies on maintenance of bioactive compounds in pumpkin by - products. Two pumpkin residue products of Hubard group pumpkins were used to obtain pumpkin powder: residue products formed in the proces s of extracting industrial pumpkin purée by heating it in a heat exchanger and treating through a sieve of pulpier; residues resulting from pumpkin juice extraction process mechanically pressed from fresh, chopped pumpkins. In order to be able to choose th e most suitable drying technology pumpkin by - products were dried in the microwave - vacuum, convective (at 40, 50, 70 and 80 °C ) and freeze - drying type dryers. For all samples total carotenes, the ascorbic acid, total phenols content (TPC) and antiradical ac tivity (DPPH ̇, ABTS ̇+ ) were determined by using standard methods. The highest total carotenes content was retained in freeze - dried pumpkin powders. The most suitable drying method for obtaining pumpkin powder with the highest ascorbic acid, total phenolic content and antiradical activity is drying in convective type drying at 80 °C temperature

FOODBALT 2017 THE EFFECT OF HIGH-PRESSURE PROCESSING ON ENTERAL FOOD MADE FROM FRESH OR SEMI-FINISHED INGREDIENTS

Abstract The enteral feeding can be defined as a delivery of nutrients directly into the stomach, called also enteral nutrition. Dietetic 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 analyse the effect of high-pressure processing on bioactive compounds in the enteral products. For this research enteral food was made using fresh or semi-finished fruit and vegetable juices. Products were processed applying high pressure, namely 400 MPa, 500 MPa and 600 MPa for 5 minutes at room temperature. All samples were tested for their content of vitamin C, total carotenes, anthocyanins, total phenols and antioxidant activity, as the control untreated enteral food samples were used. The obtained data showed that samples made from semifinished juices have higher contents of vitamin C and total anthocyanins than samples prepared from fresh juices. Similarly this was observed with total phenol content where after high-pressure treatment in samples made from heated juices it was more stable and had in higher amounts than in samples from fresh ingredients. There were no significant differences in the content of bioactive compounds between products treated at different pressures

Quality Parameters Of Wheat Bread Enriched With Pumpkin (Cucurbita Moschata) By-Products

Pumpkin processing into puree, juice, candied fruit and pumpkin seed oil results in large amount of by-products. Pumpkins are rich in carotenes, vitamins, minerals, pectin and dietary fibre. The aim of the current study was to evaluate effect of pumpkin pomace and pumpkin residue powder on wheat bread quality. The total content of carotenes was analyzed by spectrophotometric method. The initial increase of pumpkin residue addition indicated increase in loaf volume, which started to decrease at higher amounts. Sensory evaluation (appearance; surface, crust; porosity; texture, crumb; taste, and flavour) of wheat bread with pumpkin revealed very high consumer acceptance except sample with 50% pomace addition. Total carotene content and colour b* value in wheat bread increased by adding pumpkin by-products. It is recommended to add 5% and 10% of pumpkin powder and no more than 30% of pumpkin pomace (calculated per 100 kg of flour) to dough for production of wheat bread with pumpkin by-product additions

Crispbreads with Carrot and Pumpkin Processing by-Products

The results of carrot and pumpkin processing are by-products like bark and peel. Therefore, food processing waste has the potential to be converted into useful products and utilised as a source of functional compounds for consumers. Carrot and pumpkin by-products contain carotenoids, precursors of vitamin A, and dietary fibre. The consumption of these is linked to decreased incidence of cardiovascular disease, diverticulosis, and colon cancer. The aim of the study was to investigate means to increase nutritional compound content in extruded crispbread with carrot and pumpkin processing by-products. Samples were prepared from wheat flour 70%, rice flour 24%, and wheat bran 4% as control with addition of 5%, 10%, 15%, 20 % dried and grinded carrot and pumpkin by-products. Products were extruded in GÖTTFERT 1 screw Extrusiometer L series. The temperatures for extrusion zones were set at 78/83/98 °C. Total carotenoid content of the new products was determined by spectrophotometry. Total dietary fibre content was determined with Enzymatic-Gravimetric Method, AOAC 985.29. The total carotenoid content increased significantly with addition of pumpkin and carrot by-products in crispbread samples. The increase of dietary fibre content was from 9.3 mg·100 g−1 in wheat crispbread to 15.89–16.08 mg·100 g−1 in products with added carrot and pumpkin by-products

Dazadu avenu skirnu piemerotiba saldesanai

Available from Latvian Academic Library / LAL - Latvian Academic LibrarySIGLELVLatvi

Comparison of phenolic compounds and antioxidant activity of fresh and freeze-dried potatoes

ArticlePotatoes (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