Summary
Avocado seed (
Persea americana
Miller) is a by‐product of fruit processing and is considered a potential alternative source of starch. The use of starches from unconventional sources can be ...an alternative to replace modified starches as a functional ingredient in food systems. This study aimed to extract and characterise starch from avocado seed varieties Fortuna and Hass and produce aerogels. Starches were characterised by physical, chemical, thermal and morphological properties. The aerogels were produced by physical crosslinking and evaluated for water absorption capacity and physical properties. The starch extraction yield was 12%, and the granules had oval and spherical morphology. Amylose content ranged from 41.95% to 49.46%, and relative crystallinity from 22% to 25% for Hass and Fortuna, respectively. The Fortuna starch showed higher pasting temperature, peak viscosity, peak time and final viscosity values. Aerogels had excellent structural characteristics and had not deformed after 24 h of hydration; the Fortuna starch aerogels showed higher water absorption and mechanical resistance. The properties of avocado seed starch indicate a vast potential for application in food industries and for developing biodegradable packaging with excellent physical properties and excellent water retention capacity.
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.
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.
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.
Açai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the ...current knowledge regarding nonthermal technologies employed in açai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after açai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to açai sanitization. This review shows that there are still many gaps to be filled concerning açai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in açai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.
This study aimed to evaluate the effect of thermosonication (TS) on tangerine juice using an ultrasonic bath (US, 35 kHz, 750 W) at 50°C/5 min, 50°C/10 min, 60°C/5 min, and 60°C/10 min, besides juice ...pasteurized at 85°C/5 min as control. The TS increased the titratable acidity, total soluble solids, and improved the juice homogeneity (p ≤ .05), with discreet changes in the color parameters (L*, chroma, and hue). The treatment at 60°C was more effective against microbial growth, regardless of the processing time. Polyphenols and ascorbic acid remained at higher concentrations in the TS‐treated samples when compared to the control (p ≤ .05), while lower carotenoids level was observed in the treatment at 50°C/5 min (p ≤ .05). TS‐treated samples presented better antioxidant activity (p ≤ .05) when compared to the control. Thus, TS treatment (60°C/5 min) may be a promising alternative for the preservation of bioactive compounds in tangerine juice.
Practical applications
Several emerging technologies have been studied as alternatives to the conventional pasteurization of juices, like ultrasound, ultraviolet radiation, supercritic carbon dioxide, and high pressure hidrostatic. This study demonstrated that thermosonication (TS) can be used in the processing of tangerine juice using temperature of 60°C for 5 min, which exhibited the microbiological characteristics equivalent to the conventional pasteurization (85°C/5 min), without impairing the physicochemical and preserving the bioactive compounds, thus improving the antioxidant activity of the juice. The study contributes to recent research that suggests TS as a promising technology to be adopted in the fruit juice industry.
The objective of this study was to evaluate microemulsions as a protective coating for fresh cut (FC) strawberries. The effectiveness of the coating was evaluated by physicochemical, fungal ...deterioration, and sensorial analysis. The fruits were processed and submitted to different treatments: control (T1); microemulsion with citronella oil (T2); pure microemulsion (T3); microemulsion with avocado oil (T4), and emulsion containing Tween® 20 and avocado oil in water (T5). The loss of mass, deterioration by fungi, color, and anthocyanin content were evaluated. Sensory analysis was carried out for appearance, brightness, color, and odor. Of all the evaluated coatings, conservation of FC strawberries was the highest with T5, wherein the evaluated sample exhibited reduced loss of mass and deterioration by fungi, minimal changes in physical appearance, and highest anthocyanin content. The avocado oil-containing microemulsion reduced deterioration by fungi, while the microemulsion with citronella essential oil maintained tonality of the fruits and preserved anthocyanins. This study has significantly contributed to the limited literature-based information available about MEs in the food.
The objective of this work was to characterize the chemical composition of olive (Olea europaea) oils produced in Southern of Brazil and correlate it with oxidative stability. Olive oils from the ...Arbequina, Coratina, Frantoio and Koroneiki cultivars were evaluated. A completely randomized experimental design was used, in a uniform arrangement, with three replicates. Acidity value, peroxide index, specific absorption, tocopherol content, phenolic compound content, carotenoid content, chlorophyll content, fatty acid profile, and oxidative stability were determined. The oils from the Coratina and Frantoio cultivars were classified as extra virgin-oils. The olive oil from the Coratina cultivar showed the highest levels of pigments, followed by the oil from Koroneiki. The oil from the Coratina cultivar also presents higher contents of phenolic compounds (1,725.5 mg kg-1) and tocopherols (437.8 mg kg-1). The major fatty acid in all samples is oleic acid.
Resumo: O objetivo deste trabalho foi caracterizar a composição química de azeites de oliva (Olea europaea) produzidos no Sul do Brasil e correlacioná-la com a estabilidade oxidativa. Foram avaliados azeites das cultivares Arbequina, Coratina, Frantoio e Koroneiki. Utilizou-se o delineamento experimental inteiramente casualizado, em arranjo unifatorial, com três repetições. Foram determinados índice de acidez, índice de peróxidos, absorção específica, teor de tocoferois, teor de compostos fenólicos, teor de carotenoides, teor de clorofilas, perfil de ácidos graxos e estabilidade oxidativa. Os azeites provenientes das cultivares Coratina e Frantoio foram classificados como extra virgens. O azeite da cultivar Coratina apresentou maiores teores de pigmentos, seguido pelo da cultivar Koroneiki. A cultivar Coratina ainda apresenta maiores conteúdos de compostos fenólicos (1.725,5 mg kg-1) e de tocoferois (437,8 mg kg-1). O ácido graxo majoritário em todas as amostras é o oleico.
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.
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