•The essential oil of clove has strong antimicrobial and antioxidant activity.•The encapsulation process inhibits the characteristic odor of clove essential oil.•Application of the particles in ...ground meat products has similar action to nitrite.•Clove essential oil can be new alternative to synthetic food preservatives.
Clove (Syzygium aromaticum, L.) essential oil is known for its antimicrobial activity against several pathogenic bacteria. Encapsulation of clove oil was proposed as a mean to disguise its strong odor that limits its uses in food industry. Thus, the aim of this study was extraction, encapsulation and assessment of the antimicrobial and antioxidant potential of clove essential oil. The essential oil showed high DPPH scavenging capacity and low hydroxyl radical inhibition. Clove essential oil showed in vitro inhibitory and bactericidal effect against S. aureus, E. coli, L. monocytogenes and S. Typhimurium. In addition, in situ antimicrobial activity of clove oil against S. aureus was superior to nitrite. The essential oil particles encapsulated with sodium alginate and emulsifiers, showed high encapsulation efficiency, low antioxidant activity and strong antimicrobial inhibition. Similar bacterial growth was observed in meat-like products after addition of either particles or nitrite.
This study aimed to present a literature review about the characteristics, applications, and potential of avocado (Persea americana). Avocado is considered one of the main tropical fruits, as it ...contains fat-soluble vitamins which are less common in other fruits, besides high levels of protein, potassium and unsaturated fatty acids. Avocado pulp contains variable oil content, and is widely used in the pharmaceutical and cosmetics industry, and in the production of commercial oils similar to olive oil. This fruit has been recognized for its health benefits, especially due to the compounds present in the lipidic fraction, such as omega fatty acids, phytosterols, tocopherols and squalene. Studies have shown the benefits of avocado associated to a balanced diet, especially in reducing cholesterol and preventing cardiovascular diseases. The processed avocado pulp is an alternative to utilize fruits, which can be used in various value-added food products. Fluid extract of the avocado leaves is widely used in pharmaceutical products, mainly due to the diuretic characteristic of the present compounds in plant leaves. With the increasing research supporting the nutritional characteristics and benefits of avocado, the tendency is to increase the production and exploitation of this raw material in Brazil, as also observed in other countries.
RESUMO: Objetivou-se com este trabalho apresentar uma revisão da literatura sobre as características, aplicações e potencialidades do abacate (Persea americana). O abacate é considerado um dos principais frutos tropicais, pois possui as vitaminas lipossolúveis que, em geral, são deficientes nas outras frutas. Além destas, contém proteínas e elevados teores de potássio e ácidos graxos insaturados. Apresenta quantidade variável de óleo na polpa, sendo esta vastamente utilizada nas indústrias farmacêutica e de cosméticos, e na obtenção de óleos comerciais similares ao azeite de oliva. Esse fruto tem sido reconhecido por seus benefícios à saúde, especialmente em função dos compostos presentes na fração lipídica, como ácidos graxos ômega, fitoesterois, tocoferois e esqualeno. Estudos têm demonstrado os benefícios do abacate associado a uma dieta balanceada, principalmente, na redução do colesterol e na prevenção de doenças cardiovasculares. A polpa do abacate na forma processada é uma alternativa para aproveitar os frutos, passível de ser utilizada em diversos produtos alimentícios de maior valor agregado. O extrato fluido das folhas do abacateiro é muito utilizado em produtos farmacêuticos, principalmente, pelo caráter diurético de compostos presentes nas folhas da planta. Com o aumento das pesquisas que comprovam as características nutricionais e os benefícios do abacate, a tendência é aumentar a produção e exploração dessa matéria-prima no Brasil, como já acontece em outros países.
Essential oils are substances originated from plants in general. These compounds are well known to have a high biological activity, specially the antioxidant and antimicrobial. Several extraction ...techniques are employed to obtain these substances. However, the majority of these techniques require a long extraction time. In this sense, innovative and alternative extraction techniques, such as ultrasound, have recently been the target of studies. In view of the small amount of publications using ultrasonic pretreatment, this review aimed to congregate current relevant information on ultrasound-assisted extraction of essential oils. In this sense, theoretical aspects, such as the main factors that influence the performance of this technique as well as the advantages and disadvantages of the use of ultrasound as an environmental friendly alternative technique to improve the extraction of essential oil in comparison to traditional methods, are shown. Considering the available studies in the literature on essential oil extraction using ultrasonic pretreatment, low frequencies ranged from 20 to 50kWz and times ranged from 20 to 40min were used. The use of ultrasonic pretreatment represents a time reduction to near 70% in relation to the conventional hydrodistillation. Also, these conditions enabled a growth in the extraction of bioactive compounds and consequently improving the antioxidant and antimicrobial activities of essential oils.
RESUMO: Óleos essenciais são substâncias originadas de plantas em geral. Estes compostos são bem conhecidos por apresentarem elevada atividade biológica, especialmente atividade antioxidante e antimicrobiana. A fim de obter estas substâncias, são utilizadas várias técnicas de extração. A maioria destas técnicas é caracterizada por requererem um elevado tempo de processo. Neste sentido, a aplicação do ultrassom como uma técnica alternativa tem sido alvo de estudos, ganhando destaque nos últimos anos. Tendo em vista a pequena quantidade de publicações utilizando ultrassom previamente a extração, este trabalho visa reunir as atuais informações relevantes sobre a extração de óleo essencial empregando ultrassom como pré-tratamento. Além disso, aspectos teóricos como os principais fatores que influenciam o desempenho deste método e as vantagens e desvantagens do uso do ultrassom como uma alternativa para melhorar a extração de óleos essenciais de forma mais ambientalmente amigável em comparação com os métodos tradicionais são mostrados. Considerando os estudos disponíveis na literatura sobre a extração de óleos essenciais utilizando ultrassom como pré-tratamento, os melhores resultados obtidos empregam baixas frequências, que variam de 20 a 50kWz e tempos de extração entre 20 a 40min. A utilização de ultrassom como pré-tratamento possibilita uma redução de tempo de cerca de 70% em relação à hidrodestilação convencional. Além disso, estas condições permitem um aumento na extração de compostos bioativos e consequentemente melhoram a atividade antioxidante e antimicrobiana dos óleos essenciais obtidos.
Although freezing is considered one of the easiest ways to preserve the quality of food, it is harmful to strawberries. Thus, the objective of this study is to evaluate the conservation of frozen ...strawberries using gelatin as a coating and of the probiotic yeast, Saccharomyces boulardii. Strawberries were selected, sanitized and subjected to the following treatments: Treatment 1 - control 1 (strawberries stored at -18ºC); Treatment 2 - control 2 (strawberries stored at -80ºC); Treatment 3 - strawberries added with citric acid, calcium chloride and S. boulardii stored at -18ºC; Treatment 4 - strawberries with gelatin, citric acid, calcium chloride, glycerol and S. boulardii stored at -18ºC. Drip loss, soluble solids, titratable acidity, color, firmness, ascorbic acid, total phenolic compounds, monomeric anthocyanins, antioxidant activity, polyphenoloxidase activity and viability of S. boulardii were analysed. The gelatin coating added with citric acid and calcium chloride, in combination with freezing at -18ºC, reduced the drip loss, the metabolic reactions and exerted a protective effect on bioactive compounds, making it possible to use them instead of deep-freezing, mainly for agribusinesses that do not have the equipment. The use of gelatin coating on strawberries minimized the effects of freezing and promoted the protection of S. boulardii, obtaining in up to 60 days of storage the minimum viable concentration of the microorganism to exercise its functional property. On the other hand, in the absence of gelatin, S. boulardii had a negative influence on the physical-chemical parameters, in addition to showing less viability. Thus, the study demonstrated that the coating composed of gelatin, citric acid and calcium chloride can represent an interesting alternative for application on frozen strawberries enriched with S. boulardii.
O processamento mínimo do pinhao ocasiona aumento na perda de massa, deterioraçao fisiológica e crescimento de microrganismos. Assim, objetivou-se com este estudo avaliar a conservaçao de pinhao ...mínimamente processado usando revestimentos de quitosana e gelatina. Os pinhöes foram minimamente processados e revestidos com quitosana, gelatina e quitosana/gelatina, pela técnica camada sobre camada. Em seguida, foram secos sob ventilaçao forçada, acondicionados em embalagem de polietileno tereftalato e estocados a 4 °C por 10 dias. Foram realizadas análises de perda de massa, pH, açúcares redutores, vitamina C e cor, além de análises microbiológicas e análise sensorial. Benefícios foram observados com o uso dos revestimentos de quitosana e gelatina, especialmente quando aplicados pela técnica camada sobre camada. A melhor combinaçao de resultados foi obtida com a aplicaçao do revestimento quitosana/gelatina, que possibilitou a reduçao da perda de massa e do crescimento de fungos e bactérias psicrotróficas aeróbias. O revestimento nao retardou o processo de maturaçao e, consequentemente, maiores teores de vitamina C foram obtidos. Os revestimentos nao influenciaram o sabor e o aroma dos pinhöes mínimamente processados. O processamento mínimo pode incentivar o consumo da semente e, além disso, a conservaçao, utilizando revestimento comestível å base de quitosana/gelatina pela técnica layerby-layer, associado å refrigeraçao, ampliou a vida útil das sementes.
This study aimed to evaluate the physical and chemical alterations in rice starch modified by heat-moisture treatment (HMT) using an autoclave and a microwave, in association with avocado oil (AO), ...and evaluate the effects on thermal and structural properties, in vitro digestibility, and estimated glycemic index (eGI). Samples were adjusted to 30 % (w/w) moisture and 2, 4 and 8 % AO. HMT was conducted at 110 °C for 1 h in the autoclave (A0%, A2%, A4%, and A8%) and at 50 °C for 3 min in the microwave (M0%, M2%, M4%, and M8%). Both procedures did not alter the starch crystallinity pattern (type-A). Pasting viscosity, setback, relative crystallinity, and gelatinisation enthalpy decreased as the AO content increased in both HMT processes. The M8% showed reduced digestibility, decreased eGI (72.99, p < 0.05), and lower starch hydrolysis concentration (62.75 %, p < 0.05). The application of HMT with the addition of AO may be an interesting process for obtaining resistant starch since its content increased after both treatments (A8%, M4%, and M8%). The microwave process proved efficient, making it possible to use a lower temperature, less time, and less energy for modification and obtain starches with improved characteristics.
•HMT reduced the viscosity and the retrogradation of the modified starches.•The inclusion complex between amylose-lipid was confirmed by peak V-type pattern.•The HMT associated with avocado oil presents reduced in vitro digestibility and eGI.•HMT conducted by microwave is quick and efficient in rice starch modification.
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