Aims:  To study the occurrence of histidine, tyrosine and ornithine decarboxylase activity in lactic acid bacteria (LAB) isolated from natural ciders and to examine their potential to produce detrimental levels of biogenic amines. Methods and Results:  The presence of biogenic amines in a decarboxylase synthetic broth and in cider was determined by reversed‐phase high‐performance liquid chromatography (RP‐HPLC). Among the 54 LAB strains tested, six (five lactobacilli and one oenococci) were biogenic amine producers in both media. Histamine and tyramine were the amines formed by the LAB strains investigated. Lactobacillus diolivorans were the most intensive histamine producers. This species together with Lactobacillus collinoides and Oenococcus oeni also seemed to produce tyramine. No ability to form histamine, tyramine or putrescine by Pediococus parvulus was observed, although it is a known biogenic amine producer in wines and beers. Conclusions:  This study demonstrated that LAB microbiota growing in ciders had the ability to produce biogenic amines, particularly histamine and tyramine, and suggests that this capability might be strain‐dependent rather than being related to a particular bacterial species. Significance and Impact of the Study:  Production of biogenic amines by food micro‐organisms has continued to be the focus of intensive study because of their potential toxicity. The main goal was to identify the microbial species capable of producing these compounds in order to control their presence and metabolic activity in foods.

Biogenic amines play an important physiological role in mammals, and high amounts of some exogenous amines in human diet may contribute to a wide variety of toxic effects. These amines are commonly found in many foodstuffs, particularly in fermented products such as cheese, meat products, beer, wine, and ciders. Here, the level of biogenic amines in some natural ciders was examined. Twenty-four samples of cider purchased from commercial sources were analyzed by reverse-phase high-performance liquid chromatography and fluorescence detection after precolumn derivatization with o-phthaldialdehyde. Amine levels were variable, ranging from not detected to 23 mg/liter. The average level of total biogenic amines in ciders was 5.94 +/- 8.42 mg/liter. Putrescine, histamine, and tyramine were the prevailing amines being present in 50.0, 37.5, and 33.3% of the ciders studied; very small amounts of ethylamine and phenylethylamine were observed in only one sample. Other cider parameters were analyzed to determine whether they affect the biogenic amine content in ciders, and the results were evaluated by applying cluster analysis and principal component analysis. Ciders that showed lower glycerol contents and higher amounts of 1,3-propanediol had much higher levels of histamine, tyramine, and putrescine, suggesting a high activity of lactic acid bacteria during cider making and thus the need for effective control of lactic acid bacteria.

EHUko irakasleakEnpresetan aktibo ukiezinak bi eratakoak izan daitezke: a) aktibo intelektualak, «Kapital Intelektual» kontzeptuak jasotzen dituenak eta UZTAROko 66. alean aztertu genituenak (González Simón eta Guenaga, 2008), eta b) aktibo emozionalak, «Kapital Emozional» kontzeptuaren baitan biltzen direnak eta artikulu honetan aztertuko ditugunak. Lidergo-faktorea aktibo ukiezin estrategikoa da enpresetan bai «Kapital Intelektuala» bai «Kapital Emozionala» bultzatzeko. Emozioak benetako aktibo produktiboak dira enpresarentzat; gizakiarentzat, ordea, emozioak «giza garapen integralaren» funtsezko osagaiak dira. Artikulu honetan aztergai izango ditugu lidergo eraginkor bat lortzeko Adimen Emozionalaren dimentsioak eta ezaugarriak. Horrez gain, emozionalki adimentsuak diren liderren gaitasun bereizgarriak ere bistaratuko ditugu. Eta, azkenik, Adimen Emozionalean oinarrituta, liderren tipologia bat proposatuko dugu. GAKO-HITZAK: Lidergoa · Aktibo ukiezina · Kapital Emozionala · Adimen emozionala · Liderraren gaitasuna. KEY WORDS: Leadership · Intangible Assets · Emotional Capital · Emotional Intelligence · Competences of leaders. EKONOMIA Jasotze-data: 2011-09-09. Onartze-data: 2011-10-20. UZTARO 80, 51-75 54 Bilbo, 2012ko urtarrila-martxoa 2. Pertsona orok bere gaitasunak eta potentzialtasunak maila goreneraino garatu beharko lituzke, inolako salbuespenik gabe ez orainean eta ez geroan ere. Horregatik, elkartasun-mekanismoak indarrean jarri beharko lirateke giza garapen integrala munduko biztanle guztiengana heda dadin. Eta, gainera, etorkizuneko belaunaldien aukerak eta eskubideak ere ez lirateke arriskuan jarri behar, hau da, prozesu horrek denboran iraunkorra izan beharko luke. 3. Egunero hamaika emozio sortzen zaizkigu barrunbeetan, eta haiek gure harremanak eta bizimodua baldintzatzen dituzte, eta gure nortasuna eraikitzen. Izan ere, barruko emozio horiek kanpora azaleratzen zaizkigu, hots, ageriko ondorioak dakarzkigute: beste pertsonei eragiten dieten gure jokaerak, alegia. 14. Zernahi gisaz, ez dago esaterik sei lider mota horietako zein den onena edo eraginkorrena. Egoeraren arabera, bat edo beste izango da aproposagoa.