Biotechnological aspects of improving the quality of young brandy distillates

In connection with the increasing demand in high-quality raw materials for brandy production, the research intended to solve the problems of industry associated with using of low-acid or low-sugar grapes is relevant. A promising direction for improving the quality of brandy outputs is the use of yeasts with desired properties and yeast metabolism products. The aim of the research was to study the effect of biotechnological agents on physicochemical composition and quality of base wines and young brandy distillates. The experimental Kl.marxianus-based enzyme preparation with high endopolygalacturonase activity, races of yeast S.cerevisiae pure culture and L.thermotolerans strain from the Magarach collection of microorganisms of winemaking were used as biotechnological agents. Analytical studies were carried out using conventional methods, gas and liquid chromatography. The research results showed that using of yeast endopolygalacturonase based on Kl.marxianus helps to increase the yield of must (by 6 %). The L.thermotolerans strain is effective for increasing the titratable acidity of base wines (by 1.3-2.1 times). For grapes with low sugar content, it is advisable to use S.cerevisiae yeast races with a high ester-producing capacity.

An Investigation of the Organoborane/Lewis Base Pairs on the Copolymerization of Propylene Oxide with Succinic Anhydride

The copolymerization of biorenewable succinic anhydride (SA) with propylene oxide (PO) is a promising way to synthesize biodegradable aliphatic polyesters. However, the catalytic systems for this reaction still deserve to be explored because the catalytic activity of the reported catalysts and the molecular weights of produced polyesters are unsatisfied. Herein, we investigate the copolymerization of SA with PO catalyzed by the organoborane/base pairs. The types of Lewis bases, organoboranes, and their loadings all have a large impact on the activity and selectivity of the copolymerization. High ester content of >99% was achieved when performed the PO/SA copolymerization using triethyl borane (TEB)/phosphazene base P1-t-Bu (t-BuP1) pair with a molar ratio of 1/1 at 30–80 °C. Using TEB/t-BuP1 pair with the molar ratio of 4/1 at 80 °C, the turnover of frequency (TOF) was up to 128 h−1 and clearly higher than the known TOF values (0.5–34 h−1) of the PO/SA copolymerization by previously reported catalysts. The number-average molecular weights (Mns) of the resultant polyesters reached up to 20.4 kg/mol when copolymerization was carried out using TEB/t-BuP1 (1/1, in molar ratio) at 30 °C.

Screening and Application of Cyberlindnera Yeasts to Produce a Fruity, Non-Alcoholic Beer

Non-alcoholic beer (NAB) is enjoying growing demand and popularity due to consumer lifestyle trends and improved production methods. In recent years in particular, research into the application of non-Saccharomyces yeasts to produce NAB via limited fermentation has gained momentum. Non-Saccharomyces yeasts are known to produce fruity aromas, owing to a high ester production. This trait could be harnessed to mask the often-criticized wort-like off-flavor of NAB produced via limited fermentation. Six Cyberlindnera strains were characterized and screened in wort extract. Four of the six strains produced a pleasant, fruity aroma while exhibiting low ethanol production. The strain Cyberlindnera subsufficiens C6.1 was chosen for fermentation optimization via response surface methodology (RSM) and a pilot-scale (60 L) brewing trial with subsequent sensory evaluation. A low fermentation temperature and low pitching rate enhanced the fruitiness and overall acceptance of the NAB. The NAB (0.36% ABV) produced on pilot-scale was significantly more fruity and exhibited a significantly reduced wort-like off-flavor compared to two commercial NABs. This study demonstrated the suitability of Cyberlindnera subsufficiens to produce a fruity NAB, which can compete with commercial NABs. The outcome strengthens the position of non-Saccharomyces yeasts as a serious and applicable alternative to established methods in NAB brewing.

Mono- and dinuclear copper complexes coordinated on NNO-tridentate Schiff-base derivatives for copolymerization of cyclohexene oxide and cyclic anhydrides

The dinuclear copper complexes 1 and 2 performed satisfactorily to produce polyesters with controllable molecular weights and high ester linkages.

KARAKTERISASI PEKTIN DENGAN MEMANFAATKAN LIMBAH KULIT PISANG MENGGUNAKAN METODE EKSTRAKSI

Pisang merupakan buah yang sering dikonsumsi oleh manusia, baik secara langsung setelah buahnya matang ataupun diolah menjadi makanan lain. Di pulau Kalimantan, tanaman pisang banyak ditemukan di daerah Kalimantan Selatan. Kulit pisang biasanya hanya dibuang menjadi limbah, padahal di dalam pisang terdapat kandungan pektin sebanyak 22,4%. Pada penelitian ini dilakukan ekstraksi pektin dengan bahan dasar kulit pisang yang bertujuan untuk mengetahui jenis pisang yang banyak mengandung pektin, pengaruh variasi waktu ekstraksi terhadap jumlah pektin yang dihasilkan serta jenis pelarut yang menghasilkan pektin maksimum. Percobaan dilakukan memakai dua jenis pisang, yaitu pisang kepok dan pisang ambon yang dikeringkan dan diekstraksi menggunakan pelarut dengan suhu ekstraksi 80°C. Variasi waktu ekstraksi 1; 1,5 dan 2 jam, dengan pelarut HCl dan H2SO4 0,05 N. Hasil ekstraksi ditambahkan dengan etanol hingga terbentuk endapan, kemudian disaring dan di oven pada suhu 40oC selama 8 jam. Pada penelitian ini dilakukan analisa berat ekivalen, kadar metoksil, kadar galakturonat dan derajat esterifikasi. Hasil penelitian menunjukkan bahwa kombinasi waktu dan jenis pelarut terbaik untuk menghasilkan kadar pektin yang banyak, baik untuk pisang ambon maupun pisang kepok adalah ekstraksi selama 2 jam menggunakan pelarut HCl dengan kadar sebesar 14,90% untuk pisang ambon dan 10,96% untuk pisang kepok. Pektin yang dihasilkan memiliki berat ekivalen 666,67–793,65;bermetoksil rendah, yaitu 3,53%-4,34% dengan kadar galakturonat 45,06%-48,05%,termasuk pektin ester rendah dengan derajat esterifikasi 43,61%-49,23% dan termasuk pektin ester tinggi dengan derajat esterifikasi sebesar 51,28%-52,09%. Keywords: kulit pisang, pektin, ekstraksi Banana is a fruit that is often consumed by humans, either directly after the fruit riped or processed into other foods. On the island of Borneo, banana plants are mostly found in South Kalimantan. Discarded banana peels usually only become a waste, but there is pectin content as much as 22.4% in the banana. In this research, the extraction of pectin with a banana peels ingredients that aims to determine the types of bananas that contain lots of pectin, the influence of variations time extraction in the amount of pectin produced and the type of solvent that produces maximum pectin. The experiments were conducted using two types of bananas, the banana peel of Ambons and Kepok dried and extracted using solvent extraction with a temperature of 80 ° C. Variation extraction time are 1; 1.5 and 2 hours, the solvent are HCl and H2SO4 0.05 N. Extracted product added with ethanol to precipitate formed, then its filtered and dried in the oven at a temperature of 40 ° C for 8 hours. In this research, the product being analysis of equivalent weight, grade metocsil, galacturonate levels and the degree of esterification. The results showed that the combination of time and the type of solvent to generate a lot of pectin levels, both for banana Ambon and banana Kepok, was extracted for 2 hours using HCl solvent which is content of 14.90% for bananas Ambon and 10.96% for bananas Kepok .The pectin that produced has an equivalent weight of 666.67 to 793.65; low metoksil grade of 3.53% -4.34%; with galacturonate levels about 45.06% -48.05%, including low ester pectin with a degree of esterification 43.61 % -49.23% and included a high ester pectin with a degree of esterification of 51.28% -52.09% Keywords: banana peel, pectin, ekstraction

Reproductive competition in the bumble-bee Bombus terrestris: do workers advertise sterility?

Reproductive competition in social insects is generally mediated through specific fertility pheromones. By analysing Dufour's gland secretion in queens and workers of Bombus terrestris under varying social conditions, we demonstrate here that the volatile constituents of the secretion exhibit a context-dependent composition. The secretion of egg-laying queens is composed of a series of aliphatic hydrocarbons (alkanes and alkenes), while that of sterile workers contains in addition octyl esters, dominated by octyl hexadecanoate and octyl oleate. These esters disappear in workers with developed ovaries, whether queenright (QR) or queenless (QL), rendering their secretion queen-like. This constitutes an unusual case in which the sterile caste, rather than the fertile one, possesses extra components. Individually isolated (socially deprived) workers developed ovaries successfully, but failed to oviposit, and still possessed the octyl esters. Thus, whereas social interactions are not needed in order to develop ovaries, they appear essential for oviposition and compositional changes in Dufour's gland secretion (ester disappearance). The apparent link between high ester levels and an inability to lay eggs lends credence to the hypothesis that these esters signal functional sterility. We hypothesize that by producing a sterility-specific secretion, workers signal that ‘I am out of the competition’, and therefore are not attacked, either by the queen or by the reproductive workers. This enables proper colony function and brood care, in particular sexual brood, even under the chaotic conditions of the competition phase.

Herbicides compromise biological control of ragwort

In spite of ragwort flea beetle (RFB) being present on a Dannevirke dairy farm, pastures were sprayed each winter to reduce ragwort density and limit the risk of ragwort poisoning of stock. The trial on this farm from June 1999 - October 2001, aimed to determine whether herbicide (H) impacted on RFB and how H and RFB each impacted on ragwort growth and persistence. RFBfree areas were created by spraying with insecticide (I). Effects of ragwort on animal health are also reported. High ester 2,4-D (H) boom-sprayed once only, in June 1999, killed most ragwort plants and reduced RFB larvae densities to low levels before the plants died. Once new ragwort established in treatment H, the plants became infested with RFB larvae. RFB larvae were suppressed by I resulting in ragwort density declining more slowly than in treatments where RFB were not suppressed. Insecticide treatments were stopped after 15 months and, at 24 months, ragwort could not be found within the trial area. Ragwort control was attributed to the cessation of herbicide spraying allowing the RFB population to reach a sufficient density to kill both small and large ragwort plants. Sub-clinical ragwort poisoning was found in livers of culled cows that had grazed on ragwort-dense pastures. Keywords: animal health, biological control, Longitarsus jacobaeae, pyrrolizidine alkaloids, ragwort, ragwort flea beetle, Senecio jacobaea