Assessment of genotoxicity of aflatoxin M1 and B1 contaminated milks after in vitro human digestion

Introduction - Milk is considered a complete food from the nutritional point of view. Milk can be exposed to various types of contamination, such as mycotoxins. These metabolites are naturally occurring toxic compounds produced by fungi. Several studies on milk samples have reported the presence of aflatoxin B1 (AFB1) and M1 (AFM1), due to the high incidence in samples intended for human consumption, carcinogenicity proven AFB1 and resistance of the contaminants to the process of digestion, making those available for intestinal absorption. Considering these aspects, the objective of this study was to evaluate the genotoxicity of milk samples contaminated by AFB1 and AFM1 before and after the action of lactic acid bacteria using Caco-2 intestinal human cells

Inhibition of Enzymatic and Oxidative Processes by Phenolic Extracts from Spirulina sp. and Nannochloropsis sp.

U ovom je radu ispitana inhibicija enzima i slobodnih radikala pomoću fenolnih ekstrakata mikroalgi Nannochloropsis sp. i Spirulina sp., radi pronalaska inovativnog načina usporavanja procesa kvarenja hrane. Profili fenolnih spojeva ispitani su pomoću metode HPLC-UV i potvrđeni pomoću LC-MS/MS, i to u topljivim ekstraktima dobivenim pomoću metanola (slobodni fenolni spojevi) i etanola (konjugirani fenolni spojevi), te nakon hidrolize (vezani fenolni spojevi). Različitim postupcima ispitan je antioksidacijski učinak ekstrakata, te je određena njihova minimalna koncentracija potrebna za postizanje zaštitnog učinka, stabilne aktivnosti i raznovrsne primjene. Izvori fenolnih spojeva uspoređeni su pomoću spefičnog inhibicijskog učinka (izraženog u %/(min·μg), tj. procjenom inhibicije ABTS, DPPH, α-amilaze i peroksidaze. Maseni udjel slobodnih fenolnih kiselina u ekstraktu mikroalge Spirulina sp. bio je 628 μg/g, a u ekstraktu Nannochloropsis sp. 641 μg/g. Fenolni ekstrakt Nannochloropsis sp. pokazao je veću aktivnost inhibicije ABTS (1,3 %/(min·μg)) i peroksidaze (0,4 %/(min·μg)), a ekstrakt iz Spirulina sp. bolje je inhibirao α-amilazu (0,07 %/(min·μg)). Zaključeno je da se fenolni ekstrakti jestivih mikroalgi mogu primijeniti u prehrambenoj industriji kao prirodna zaštita od endogenih i egzogenih hidrolitičkih i oksidacijskih procesa.This study investigates the capacity of phenolic extracts from microalgae Nannochloropsis sp. and Spirulina sp. to inhibit enzymes and free radical activities, intending to find an innovative way to slow down food damage. HPLC-UV and LC-MS/MS served to determine and confirm, respectively, the phenolic acid profiles in the soluble methanolic (free phenolic) and ethanolic (conjugated phenolic) fractions, and after hydrolysis (bound phenolic fractions). Different procedures measured the antioxidant activity of the extracts to estimate the minimal concentration for the protective effect, stability and versatility of activity. The ability to inhibit the oxidative process (ABTS and DPPH), α-amylase and peroxidase activities were estimated as specific inhibition (%/(min·μg)) for better comparison between the phenolic sources. The phenolic acid mass fractions in the free phenolic extracts from Spirulina sp. and Nannochloropsis sp. were 628 and 641 μg/g, respectively. Phenolic extract from Nannochloropsis sp. showed the highest value of ABTS inhibition (1.3 %/(min·μg)) and highest inhibition of peroxidase activity (0.4 %/(min·μg)). The extract from Spirulina sp. was a better inhibitor of α-amylase activity (0.07 %/(min·μg)). Therefore, the phenolic extracts from the edible microalgae may be applied in food industry as natural protector against endogenous and exogenous hydrolytic and oxidative processes

Microalgas Nannochloropsis sp. E Spirulina sp. e seu potencial como fonte de ácidos graxos essenciais

As biomassas de Nannochloropsis sp. e Spirulina sp. foram caracterizadas quanto a composição de diferentes ácidos graxos, visando definir o potencial funcional como fonte de ácidos graxos essenciais. A extração dos lipídios foi realizada a frio com mistura de clorofórmio:metanol, para derivatização dos ácidos graxos foi empregado o reagente BF3 sob refluxo, e a identificação e quantificação deles foi realizada em cromatografo gasoso acoplado a detector por ionização de chama. A biomassa de Nannochloropsis ps. apresentou 3%, 87% e 11% de ácidos graxos saturados, monoinsaturados e poliinsaturados, respectivamente. Enquanto que a biomassa de Spirulina sp. continha 31%, 63% e 6% destas mesmas classes de ácidos graxos. Sendo que o composto majoritário encontrado na biomassa de Nannochloropsis sp. foi o ácido elaídico (62%) e na Spirulina sp. o palmitoléico (41%). A proporção de ácidos graxos quanto a presença de insaturações mostrou que a Nannochloropsis sp. apresenta o dobro de poliinsaturados comparativamente a Spirulina sp

EFEITO DOS TRATAMENTOS TÉRMICOS SECO E ÚMIDO NOS NÍVEIS DE AFLATOXINA B1 E OCRATOXINA A PRESENTES EM FARELO E FARINHAS CEREAIS

  The effect of dry and wet thermal treatment was studied on levels of aflatoxin B1 and ochratoxin A contaminating simultaneously defatted rice bran, wholemeal wheat and wholemeal oat, employed in the production of baby food. Each  sample was artificially contaminated with different concentrations of each mycotoxins (3 to 95 ppb) and the thermal treatments  were  carried out in oven at 220ºC and  autoclave (121ºC; 1,1 Pa man) during  5 and 15 minutes. The residual mycotoxins were quantified, after confirmation by chemical derivation, as thin layer multimethod.  The thermal treatments and exposure time decreased the levels of mycotoxins until levels lower than the detection limits in 45 and 64% of the studied condition for aflatoxin B1 and ochratoxin A respectively. The defatted rice bran was best decontaminated by the wet thermal treatment and the wholemeal by dry treatment.Estudou-se o efeito dos tratamentos térmicos seco e úmido sobre os níveis de aflatoxina B1 e ocratoxina A presentes simultaneamente em farelo de arroz desengordurado e farinhas integrais de trigo e aveia, utilizados para a produção de alimentos infantis. Cada amostra foi contaminada com diferentes concentrações de cada micotoxinas, (3 a 95 ppb) e os tratamentos térmicos realizados em estufa a 220ºC e autoclave (121ºC; 1,1 Pa man) durante 5 e 15 minutos. As micotoxinas residuais foram quantificadas, após confirmação por derivação química, conforme o multimétodo de cromatografia em  camada delgada. Os tratamentos térmicos e os tempos de exposição  ocasionaram diminuição nos  níveis das micotoxinas a valores inferiores aos limites de detecção em 45 e 64% das condições estudadas para a aflatoxina B1 e ocratoxina A, respectivamente. O farelo de arroz desengordurado foi mais susceptível à descontaminação pelo calor úmido, enquanto as farinhas pelo calor seco