Ripening Research Articles

Kvašení a zrání. Stav našich současných znalostí.

Za hlavní faktory konvenčního hlavního kvašení a dokvašování považujeme: složení mladiny (volný aminodusík v % celkového dusíku, obsah zinku), intenzitu provzdušnění, stejnoměrné rozptýlení kvasinek, charakteristiku kvasnic (kmen, ošetření sběr), počet buněk, jakož i kontrolovanou rozkvasnou fázi. Pro zrání jsou důležité výchozí hodnota vicinálních diketonů, počet kvasničných buněk a teplota.Dvoudenní zrání při teplotě20 °Cpo předchozím studeném hlavním kvašení nachází stále více přívrženců. Pro teplé kvašení pod tlakem jetřeba vytvořit stejné podmínky a dbát na tytéž faktory, má-li být kvašení a dokvašování uspořádáno do 7denního rytmu, který je pro organoleptické vlastnosti piva výhodný. Studené ležení (skladování) musí být u urychlených (zkrácených) postupů vedeno asi 1 týden při teplotě pod O C. Specialisté v oboru fyziologie kvasinek se mohou pozastavit nad tím, že kvasinky spodního kvašení nedokáží vzdorovat kolísavým tlakovým podmínkám při kvašení ve velkých nádobách nebo dokonce při kvašení pod tlakem déle než přes několik generací. Je tedy třeba připravovat si pomnožováním stále čerstvé kvasnice, abychom nepřekročili dobu, v jejímž rámci si provozní kvasnice udržují své optimální vlastnosti. Pro pivovarníka je tím toto téma vyřešeno, i když jej bude dále zaměstnávat úloha získávání zbytkového piva z odpadních kvasnic. Vzniká potřeba dodatečných zařízení k oddělování kvasnic od piva a pokud možno "neutrálních" způsobů využití tohoto piva. Časový harmonogram kritických momentů při získávání a využívání piva z kvasnic vyžaduje pečlivé zvážení z hlediska biologických i kvalitativních, popř. organoleptických.

Phenolic compounds in persimmon during maturation and on-tree ripening

Changes in weight, Brixo, moisture and phenolic substances, extractable with water, methanol and aqueous methanolic solution, were determined during maturation and on-tree ripening (120 days) of persimmon. Fruit weight increased during maturation (40 to 169 g/fruit) and then decreased to an average value of 145 g/fruit on ripening. Brixo increased throughout from 15 to 20 while moisture content exhibited irregular trend. Maturation time and extracting solvents significantly influenced the polyphenolic compounds (P < 0.05). The concentration of sinapine, catechin and procyanidine in relation to different extractants showed an overall decreasing pattern during maturation and ripening. However, total phenolics exhibited an upsurge after 60 days while leucoanthocyanidine values increased between 15–75 days followed by reduction with each solvent. An overall significant linear correlation (r = −0.811 to −0.916) was found between the loss of polyphenols except leucoanthocyanidine and maturation/ripening time (P < 0.05). Phenolische Verbindungen in der Dattelpflaume wahrend der Entwicklung und Baumreifung Wahrend der Entwicklung und Baumreifung (120 Tage) der Dattelpflaume werden die Veranderungen von Gewicht, oBrix, Feuchtigkeit und phenolischen Substanzen nach Extraktion mit Wasser, Methanol und wasriger Methanollosung ermittelt. Das Fruchtgewicht erhoht sich wahrend der Entwicklung von 40 auf 169 g/Frucht und nimmt dann bis zu einem mittleren Wert von 145 g/Frucht wahrend der Reifung ab. Der Brix-Wert erhoht sich in der untersuchten Zeit von 15 auf 20°, wahrend der Gehalt an Feuchtigkeit einem irregularen Trend folgt. Die Entwicklungszeit und die zur Extraktion verwendeten Losungsmittel beeinflussen den Gehalt an phenolischen Komponenten (P < 0,05). Die Konzentration an Sinapin, Catechin und Procyanidin zeigen in Abhangigkeit von den verschiedenen Losungsmitteln insgesamt Abnahmen wahrend der Entwicklung und Reifung. Die Gesamtphenole weisen jedoch nach 60 Tagen eine vorubergehende Erhohung auf, wahrend der Gehalt an Leukoanthocyanidin mit allen Losungsmitteln zwischen 15 und 75 Tagen zunimmt und danach wieder reduziert wird. Insgesamt werden signifikante, lineare Korrelationen (r = −0,811 bis −0,916) zwischen Abnahme an Polyphenolen (ausgenommen Leukoanthocyanidin) und der Entwicklungs-/Reifungszeit (P < 0,05) ermittelt.

Growth and ripening of main-crop fig.

The main crop of the «common» type fig cv. 'Rampelina' exhibited a three-stage growth cycle: two periods of rapid development interrupted by a slow growth phase; the climacteric and the increase in ethylene occurred in the latter rapid stage. The compositional and physiological changes marking fruit development were recorded in fruits divided by weight into six groups. Figs in the highest weight group harvested at cell distension showed an increase in ethylene production commensurate with the onset of ripening. Respiration always increased at mid-August, though in figs under 30g without changes associated with ripening. Examination of morphological changes in flowers evinced various development stages.

Pharmacological modulation of cervical compliance in the first and second trimesters of pregnancy.

PIP: Health practitioners use many methods and agents to bring on cervical ripening in early pregnancy, such as intracervical tents and pharmacological techniques, to induce a therapeutic abortion. Prostaglandins alter myometrial and cervical tissue and are the most often used pharmacological technique. Reduced collagen concentration, an increase in water volume, an increase in prostaglandins (PGE2, PGI2, and PGF2 alpha), and a change in the glycosaminoglycan (GAG) content coincide with cervical ripening, yet the mechanism responsible for these changes is obscure. Prostaglandins appear to cause the breakdown of collagen or change the GAG/proteoglycan content. Research shows that prostaglandins can initiate cervical ripening at any stage of pregnancy. Estradiol stimulates prostaglandin production thereby al so inducing cervical dilation. Relaxin also demonstrates an ability to ripen the cervix. In addition, mifepristone (RU-486) is gaining acceptance as a cervical ripening agent. In fact, RU-486 and gemeprost have at least 95% success rate compared to 92% for gemeprost alone or 85% with RU-486 alone. The only effective and acceptable prostaglandins to use at gestation of 0-8 weeks are sulprostone, gemeprost, and 9-methylene-PGE2. At t his gestational age, pharmacological modulation is all that is needed. Even though they are effective (abortion rate 90%), side effects are expected to occur (pain, nausea, and vomiting). Similarly, prostaglandin analogues are preferable for cervical ripening in women at 8-12 weeks gestation. Suction curettage or other surgical techniques then are used to remove the conceptus. At 12-16 weeks gestation, many physicians prefer the same protocol as that of 8-12 weeks gestation. Other choose to infuse PGE2 and saline into the amniotic fluid to stimulate uterine contractions. Another procedure at 12-16 weeks involves 1mg vaginal pessaries of gemeprost every 3 hours to ripen the cervix and stimulate contractions. After 16 weeks, the methods for 12-16 weeks still apply.

Cervical distensibility changes in pregnancy, term, and preterm labor.

T he changes in the mechanical behavior of cervical tissue observed at the end of gestation are in fact due to histological and biochemical changes. The inner circumference of the cervix in the nongravid state, having a well-ordered collagenous network, cannot reach the inner circumference value necessary to accommodate the fetal head. Therefore, the rearrangement of the collagen fibers into a more disorganized, looser network during pregnancy seems to be an important process in cervical ripening. In support of this idea are the numerous histological studies showing disorganization of collagen fibers at term in animals1,2 and women. 3,4 Biochemical changes of the cervical connective tissue ground substance components (eg, proteoglycans, glycoproteins, water content) are likely to play a major role in the disorganization of the collagen network. 5~6 In the human cervix the fibroelasticity seems to dominate, since the test results observed by several authors’.8 with the uterine cervix closely resemble the results for fibroelastic materials. In obstetrics, it is of great interest to quantitatively determine mechanical characteristics of the uterine cervix, particularly the ease with which the cervix can be dilated, in order to describe and understand the mechanism of human cervical dilatation. Digital internal pelvic examination is a fast and simple technique to study physical characteristics of the uterine cervix, and a number of clinical systems of quantifying cervical ripeness have been devised, most notable that of Bishop.g With these systems, a low score indicates an unripe cervix, and a high score, a ripe cervix. Unfortunately, these methods are subjective, and amalgamate several parameters, eg, that cervical consistency is presumably related to biochemical connective tissue changes whereas the other elements of the pelvic score (dilation, effacement, position, level of the presentation) are most likely related to myometrial activity. This is why several instruments were designed to quantitate the mechanical properties of the uterine cervix related to connective tissue changes (measurement of cervical compliance and cervical consistency),7,810 but the clinical application of such methods is very difficult and/or not accurate enough. We have developed a cervicotonometer to measure a distensibility index in the clinical practice that is based on the values of the force used to open the cervix and the inner diameter of the cervix obtained with each force used. The use of this instrument and results obtained with it will be described in this article.

The role of proteoglycans in cervical dilatation.

The extracellular matrix of fibrous connective tissues contains, besides collagen, a number of macromolecules, including fibronectin, laminin, and proteoglycans. Even though only little is known about the function of these matrix molecules, especially the proteoglycans have been considered to be associated with the biomechanical properties of connective tissues. They constitute a heterogeneous family and are characterized by rather different core proteins with different characteristics to which one to a hundred glycosaminoglycans are attached. The glycosaminoglycans themselves constitute a family of macromolecular polysaccharides with different characteristics. They were formerly called acid mucopolysaccharides. Most proteoglycans also contain a number of oligosaccharides, and some proteoglycans are also substituted with fatty acids. For many years, glycosaminoglycans and proteoglycans were considered only to form the ground substance between the collagen fibers of cartilage and fibrous connective tissues, and to determine the hydration of these tissues. However, during the last 10 years the application of molecular biological techniques to the study of the core proteins and the polysaccharide components have shown a marked diversity in their structure and functions. Thus proteoglycans are involved in cell adhesion, differentiation, and proliferation. They have also been postulated to play a role in the filtering function of the kidney and to constitute protease inhibitors and cell receptors. Furthermore, the progression of cancer cells has been shown to involve increased gene expression of some small proteoglycans that modulate the extracellular matrix. ’ Proteoglycans are most likely involved in the cervical ripening that usually takes place at term of pregnancy before start of labor. They might affect the mechanical properties of the cervix via their ability to modulate the collagen component.

The reflowering of prickly pear Opuntia ficus indica (L.) Miller : influence of removal time and cladode load on yield and fruit ripening

The reflowering of prickly pear Opuntia ficus indica (L.) Miller : influence of removal time and cladode load on yield and fruit ripening

İkinci Trimester Missed Abortus Ve İntrauterin Ölü Fetus Olgularında Prostaglandin E2 Ve Oksitosin Kullanımı

The use of oxytocin and PGE2-gel in cases of second trimestr missed abortion and intrauterine fetal death ✓34 women who had missed abortion or intrauterin exitus and required surgical termination of pregnancy from 12-24 weeks of gestation were treated with intracervical PGE2-gel and oxytocin infusion. The patients were divided into two groups. First group were treated with only oxytocin. There was signilicant difference between the two groups according to mean duration of abortion (p<0.05). According to this preliminary experience the intracervical application of the new ready-for use pge2-gel repesents a practicable and efficient method for abortion and preoperative cervical ripening. Intracervical application of gel didn't have any side effects, not induced hypertonic contractions but only locally riped. We didn't confront any complications in the Pge2-gel treated group. ✓ Gebelik haftasi 12-24 hafta arasi olan, missed abortus veya intrauterin eksitus tanilari ile gebeliklerinin cerrahi olarak bosaltilmasi gereken 34 olguda intraservikal PGE2 jel ve oksitosin kullanildi, olgular iki gruba ayrildi. Ilk grupta intraservikal PGE2-Jel ve oksitosin kullanilirken 2.grup olgularda ise sadece oksitosin infuzyonu yapildi. Ortalama dusuk eylemi ,suresi bakimindan gruplar arasindaki farkin onemli oldugu saptandi (0.02<p<0.05).

4779524 Apparatus for controlling the ripening of fresh produce: William Wade assigned to Nabisco Brands Inc

4779524 Apparatus for controlling the ripening of fresh produce: William Wade assigned to Nabisco Brands Inc

カキ果実の発育&amp;bull;成熟過程における糖組成の変化とインベルターゼ活性との関連について

カキ果実の発育&amp;bull;成熟過程における糖組成の変化とインベルターゼ活性との関連について

マイワシ・サクシニル化タンパク質乳化物のカード形成とその熟成

マイワシ・サクシニル化タンパク質乳化物のカード形成とその熟成

Changes of polyuronides in kiwifruit during ripening.

Changes of polyuronides in kiwifruit during ripening.

Detection of polygalacturonase in kiwifruit during ripening.

Detection of polygalacturonase in kiwifruit during ripening.

バナナ果実の成熟誘導に対するエチレン処理の時間, 濃度及び温度の関係

バナナ果実の成熟誘導に対するエチレン処理の時間, 濃度及び温度の関係

DYNAMICS OF SOME BIOMACROMOLECULES DURING EMBRYOGENESIS IN RICE

The DNA and RNA content as well as cell number per embryo increased rapidly during the differentiation of rice embryo (6 to 13 days after anthesis), and tended then to become constant. But during the 18 to 25 days after anthesis, the quantity of RNA rose again. The protein content changed almost in correspondence with the dynamic variation of RNA content. The starch accumulation and utilization performed a regulatory function on embryogenesis. With the development and maturation of embryo the degradation of 18S rRNA in the embryos of frozen-stored seeds reduced regularly showing that the rRNAs (ribosomes) gradually accumulated and were protected in some ways during embryo ripening. In the light of discussion about the relationships between the dynamics of biomacromolecules and the progress of embryogenesis, it was suggested that the developmental progress of rice embryogeny was divided into four stages, namely, the proembryo-, differentiation-, maturation- and quiescence-stage.

Effect of cyclic plastic deformation on elevated temperature ostwald ripening of an alloy with coherent precipitates

Alliage Fe-2,5% at. Ni-5,7% at. Al-2% at. Mo. Etude du grossissement augmente des precipites β' de type NiAl et de structure B2 dans cet alliage cubique centre sous l'influence de deformations de fatigue

Ripening and spoilage of sugar salted herring with and without nitrate

SummaryThe technological effect of nitrate and the possible role of this compound in the formation of volatile nitrosamines during ripening and spoilage of sugar salted herring have been examined. In total, 600 barrels of fish with various amounts of nitrate added to the curing salt were prepared and stored under commercial conditions. During storage (18 months) the organoleptic, microbiological and chemical changes were studied. Additionally, a number of model experiments were carried out to evaluate the effect of nitrate on microbial growth and chemical changes. It was found that addition of nitrate significantly influences the colour of the fish while texture and flavour are not affected. Based on both the practical experiments and the model studies it is concluded that nitrate per se does not inhibit any microbial growth. Growth of strict anaerobes does not occur until the substrate is depleted of TMAO, and nitrate is effective in delaying the most common type of spoilage by delaying the TMAO reduction.Small amounts of nitrosodimethylamine—up to 2.9 ppb has been detected—was formed in the sugar salted herring, but the addition of nitrate to the curing salt had no influence.

EXPERIENCES WITH RIPENING TESTS FOR APPLES

EXPERIENCES WITH RIPENING TESTS FOR APPLES

Investigating the kinetics of viscose ripening by thin-film spectrophotometry

Investigating the kinetics of viscose ripening by thin-film spectrophotometry

Relationship between the Emulsifying Capacity of Cheese and the Size of Casein during Ripening

Relationship between the Emulsifying Capacity of Cheese and the Size of Casein during Ripening