An Integrated Approach for Analysis of Higher Penetration of Variable Renewable Energy: Coupling of the Long-Term Energy Planning Tools and Power Transmission Network Models

Many studies and scientific papers have been published that consider the integration of renewable sources in energy systems, using the least-cost optimization models as a long-term generation expansion planning tool. Supplementary to these analyses, this paper focuses on the transmission network capacity for acceptance of variable renewable energy. The hypothesis is that the simplified electric power transmissions system in the long-term planning modelling tools does not reflect properly the capacity for integration of the variable renewable energy. An integrated approach is applied with aim to incorporate the grid expansion needs and costs (using direct current load flow analysis), necessary for increased renewable electricity penetration. The already developed MARKAL-Macedonia model will be used as a case study. After several iterations and feedback loops between the MARKAL-Macedonia and the network model, the expected outcome is to achieve a new cost-effective solution for deployment of variable energy on a larger scale

DETERMINATION OF SOME PARAMETERS IN WINE PRODUCED FROM CLONE AND POPULATION OF VRANEC VARIETY VINES

Vranec variety is the most planted red grape variety in our country for production of high quality wine.  This investigation was carried out on two vineyards, one with clone material and the other with population indigenes for old Macedonian vineyards. Both were located in Gevgelija-Valandovo region with sub-mediterranean clime conditions. The scope of this investigation is to determine some chemical parameters that influence on the quality of wine, as alcohol strength, specific gravity, total extract, total acids, volatile acids, pH, free and total SO2. Also, the content of total phenols, total anthocyanins, hue, intensity and percent of red, yellow and blue color were analyzed. Five wine experts were involved for the sensory descriptive evaluation of the investigated wines and the results were presented on spider chart

INVESTIGATION OF ORGANOLEPTIC CHARACTERISTICS OF POMEGRANATE (PUNICA GRANATUM L.) VARIETIES

Investigation of organoleptic characteristics and determination of some biochemical compounds content in the fruit of eight traditional pomegranate (Punica granatum L.) varieties and types: Lifanka, Bejnarija, Karamustafa, Ropkavac, Valandovska kisela, Lifanka clone, Zumnarija and Hicaz, from Valandovo area (North Macedonia), was performed. Fruit from Valandovska kisela and Hicaz varieties are characterized with the lowest value of pH and also with highest content of citric acid. The content of fructose sugar prevails over the content of glucose in 1,1 ratio. Anthocyans are the most common in fruits from Hicaz variety. The Valandovska kisela variety has the highest content of phenols. The fruits from Ropkavac and Zumnarija varieties have the highest content of flavan-3-ols which give them a characteristic flavor. According to organoleptic evaluation of external fruit appearance, the best ranked is the Karamustafa variety. According to the internal characteristics, i.e. the fruit aril, again stood out as the best the Karamustafa variety, by all parameters. The respondents are pointed out also Ropkavac and Bejnarija varieties in evaluation of aril flavor and aroma, such as very good varieties, especially by the aril juiciness. According to all organoleptic (external and internal) characteristics, the highest ranked is Karamustafa variety which is recommended as a perspective variety of pomegranate for spreading in R North Macedonia

DESCRIPTION OF THE MORPHOLOGICAL AND TECHNOLOGICAL CHARACTERISTICS OF THE PLANT GOJI BERRY

Goji berry is relatively a new plant introduced in the Republic Macedonia. It is prevalent on limited small plantations to a controlled breeding conditions and providing a yield which is immediately placing on the market and awakens interest in further expansion of its production. This plant (Lycium barbarum or Lycium chinense), belongs to the family Solanacea and characterized by very favorable chemical composition of the fruit with high nutritional, energy and antioxidant value. Therefore, this plant is a large application in dietary recommendations for the prevention of many diseases and as a natural organic product for general strengthening of the human organism. From another aspect, goji berry requires minimal growing conditions aimed at irrigation and treatment with pesticides and it belongs in adaptable resistant plants for organic production. Also, this plant has good genetic predispositions, easily reproduced and has favorable characteristics; cytogenetic status, germination of seeds, regenerative ability, ability to clonal selection and in vitro - propagation. Its morphological construction is easy for examination of scientific purposes. Considering that in the fruit of this plant has similar chemical substances as it has in the grape, but enormously more, in our research experience made by fermentation (actually vinification) of the two types of Goji berries - sweet andbitter. The goal was to get fermented products similar to wine, but with improved chemical composition and strong antioxidant power.But after analyzing the obtained product, it can be concluded that by increasing the quantity of antioxidant substances during the vinification, however sensory evaluation of the final product is low. Goji berry should be consumed in fresh or dried form or may be a supplement of some special wines (with high sensory evaluation and strong antioxidant substances)

EXAMINATION OF THE CONTENT OF SOME ANTIOXIDANT SUBSTANCES IN SOME AUTOCHTHONOUS GRAPEVINE VARIETIES (VITIS VINIFERA L.) IN R.N. MACEDONIA

In this paper, some bioactive antioxidants have been tested in several grape varieties (Vitis vinifera L.) present in R.N. Macedonia. Grapes are a source of various nutrients that are beneficial to the human body in many ways. A grape, as a raw material and its final processing - wine is a complex of many chemical substances and compounds that are responsible for many visible and sensory characteristics that are manifested in varieties (phenotypic). Those chemical compounds are; carbohydrates, organic acids, alcohols, aldehydes, esters, vitamins, polyphenols, minerals, nitrogen compounds, etc. Specifically, in our case, vitamin C (ascorbic acid) and phenolic compounds (total phenols, anthocyanins, flavan-3-ol and antioxidant activity) were tested in several autochthonous grape varieties and one standard variety (Belo zimsko, Stanushina, Crn valandovski drenok, Crven valandovski drenok and Palieri as standard). The tested chemicals are of great importance in their consumption in the human diet. They have antioxidant, anti-inflammatory, antimicrobial, anticancer, anti-mutation effects and reduce the risk of cardiovascular, degenerative and other chronic diseases. The most important for this group of compounds is that they determine the color, astringency, bitterness and some organoleptic and sensory characteristics of grapes and wine

ПАКУВАЊЕ НА ПРЕХРАНБЕНИ ПРОЗИВОДИ ВО МОДИФИЦИРАНА АТМОСФЕРА ОД ГАСОВИ

За да можеме да го зачуваме квалитетот и безбедноста на прехранбените производи подолг временски период неопходно е да се направи соодветен избор на амбалажа за нивно пакување и чување. Изборот на амбалажата зависи од физичката и хемиската природа на производот, како и од карактеристиките на материјалот за пакување. Во посоледно време се нудат современи решенија за пакување на храна кои од една страна го продолжуваат рокот на траење, а од друга го намалуваат количеството на амбалажниот отпад. Еден од нив е пакување на храна во модифицирана атмосфера на гасови (Modofied atmosphere packiging, MAP). Оваа техника се изведува такашто воздухот којшто се наоѓа во околината на храната спакувана во дадена амбалажа се заменува со друг гас (азот, кислород, аргон, јаглерод диоксид, јаглерод моноксид, водород и др.) или смеса од гасови со посебен состав прилагоден на производот којшто се пакува. Составот на гасовите е важен параметар, а наговиот избор зависи од типот на производот што се пакува, материјалот за пакување и температурата на којашто ќе се чува. Различни типови на намирници може да се пакуваат во модифицирана атмосфера на гасови: месо и преработки од месо, риби и морска храна, леб и пекарски производи, млеко и млечни производи, овошје и зеленчик и др. Со цел да се истита влијанието на MAP пакувањето врз продолжување на рокот на траење на броколи следени се промените кај нив во период од 14 дена. Броколите се пакувани при три различни MAP услови (макроперфорирани кеси, микроперфорирани кеси и комерцијални кеси), како и во кеса во која има атмосферски воздух. Четирите примероци коишто се чувани во ладни комори на температура од 1,5 °С десет дена, на 17°С два дена и на 20°С два дена. Рокот на траење на броколите во различни услови на складирање во ова истражување е оценет со помош на различни физиолошки параметри и параметри за квалитет. Следени се следниве парамтери: уделот на CO2 и O2 за време на чувањето, физиолошките промени за време на складирањето, физиолошките загуби на тежина (PLW), образување на етилен. Понатаму од параметрите за квалитет следени се: промена на бојата, распаѓање за време на чувањето, вврстина на броколите и општата прифатливост на броколите