One approach to improving sustainable food production is to add value to fruit by-products, which are currently used as animal feed or discarded, yet may be useful sources of natural antioxidants due to their phenolic compounds. Hence, the present work aimed to produce and evaluate two products prepared from an anthocyanin-rich extract of a blackberry by-product through freeze-drying. Maltodextrins with 10 and 20 dextrose equivalent (DE), were assessed as the carrier matrices. The maltodextrin DE did not significantly influence the mean diameter and solubility of the particles. Morphological analysis revealed that all the particles exhibited a broken glass structure and shriveled surfaces. Comparatively, better results were obtained from the maltodextrin 10 than 20DE powders, regarding anthocyanin retention in the drying process, hygroscopicity, moisture content, acidity, water activity and color indices (P < 0.05). The results suggest that blackberry by-products contain valuable biocompounds, namely anthocyanins. Therefore, the anthocyanin extraction, concentration and microencapsulation with maltodextrin 10DE, presented a potential approach to using blackberry byproducts as food colorants or healthy ingredients.

ABSTRACT

Citrus seeds represent substantial wastes of citrus-processing. Oils extracted from orange (Citrus sinensis), lemon (Citrus limon) and tangerine (Citrus reticulata) seeds were investigated. The seeds were removed from the fruits, washed, dried at room temperature, ground and the oils extracted using a Soxhlet extractor. The seed oils were analyzed in terms of the lipid content, fatty acid, tocopherol and carotenoid compositions, total phenolic content, oxidative stability and the radical-scavenging activity. The oil content of citrus seeds ranged from 34.92 to 41.66%. The oils showed high degrees of unsaturation and essential fatty acids. Oils exhibited also natural antioxidants specially tocopherols and phenolic compounds. Oxidative stability and antioxidant activity were influenced by unsaturated fatty acids and tocopherol contents in the analyzed oils.Keywords: orange, lemon, tangerine, fatty acid, antioxidants *To whom correspondence should be addressed. E-mail: njorge@ibilce.unesp.br IntroductionThe genus Citrus, belonging to the Rutaceae family, is characterized by evergreen, small trees or shrubs, often spiny. The Rutaceae comprises about 150 genera and 1,500 species including some of the most cultivated and consumed fruits of the world, such as C. sinensis (orange), C. reticulata (tangerine), C. paradisi (grapefruit), C. limon (lemon) and C. aurantifolia (lime). These fruits, probably of Southeast Asian origin, are produced all around the world in many countries that have tropical and subtropical climates (Kale and Adsule, 1995).Brazil is one of the biggest global hubs in producing fruits, especially citrus. São Paulo state stands out for the cultivation of orange, lemon and tangerine. Great part of their production intends for juice making, which generates tons of waste, such as seeds that are often disposed, and thus increasing environmental pollution.Besides a large scale in natura consumption, vast quantities of citrus fruits are processed mainly to obtain juice, but also, in the canning industry, to produce marmalade, and by the chemical industry to extract flavonoids and essential oils. Wastes from industrial processing are composed of peels, seeds and pulps representing 45 to 58% of the raw processed fruit (El-Adawy et al., 1999).Several phytochemicals may be detected in edible seed oils including tocopherols, carotenoids, phenolic and polyphenolic compounds, and special fatty acids such as α-linolenic acid. In addition to the phytochemical components, other important oil properties include oil stability and antioxidant activity.Citrus seeds contain from 26 to 42% of oil and are a good source of K, Ca, Na, Fe and Mg (El-Adawy et al., 1999). Saïdani et al. (2004) verified that oils extracted from Tunisian citrus seeds are mostly constituted of triacylglycerols that are rich in unsaturated fatty acids. Oils from citrus seeds native to Pakistan also showed to be an important source of essential fatty acids and tocopherols showing good potential for both human consumption and industrial applications (...

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Turmeric oleoresin is a colorant prepared by solvent extraction of turmeric (Curcuma longa L.). Curcumin, the major pigment present in turmeric, has been described as a potent antioxidant, anti‐inflammatory and anticarcinogenic agent. Turmeric pigments are lipid soluble and water insoluble and are sensitive to light, heat, oxygen and pH, which can be overcome by microencapsulation of turmeric oleoresin. The aim of this work was to investigate microencapsulation of turmeric oleoresin by complex coacervation using gelatin and gum Arabic as encapsulants and freeze‐drying as the drying method. The coacervation process was studied by varying the concentration of biopolymer solution (2.5, 5.0 and 7.5%) and the core material : total encapsulant ratio (25, 50, 75 and 100%). Microcapsules were evaluated for encapsulation efficiency, morphology, solubility and stability to light. Encapsulation efficiency ranged from 49 to 73% and samples produced with 2.5% of wall material and 100% core : encapsulant ratio showed better stability to light. Practical Applications This paper presents an optimized method to encapsulate turmeric oleoresin by complex coacervation using gelatin and gum Arabic as wall materials, producing dry colorant microcapsules with improved solubility in aqueous formulations.

Curcumin yellow dye is considered as an antioxidant, susceptible to light and oxidative degradation. Microencapsulation improves its stability and facilitates its use. This work aimed to investigate the effects of different formulation wall materials (gum arabic, a binary mixture of maltodextrin and modified starch, and a ternary mixture of gum arabic, maltodextrin and modified starch) and different drying methods (for spray and lyophilization) on the stability of microcapsules of turmeric oleoresin. The drying method affected retention curcumin powder in the drying process and storage of the microcapsules under incident light. Curcumin retention during lyophilization was greater than spray drying, but showed the opposite behavior during storage; spray-dried capsules had a higher retention of curcumin after 8 weeks under light exposure. As a result, the ternary mixture of gum arabic, modified starch and maltodextrin was more effective to prevent loss of curcumin and color changes in the microcapsules. PRACTICAL APPLICATIONSThe main function of turmeric oleoresin is to give color and tempered aroma in certain foods such as pickles and mustard. The knowledge of encapsulation techniques allows the control of the bioactive components, the release time and dosage of turmeric oleoresin in the structure of the food. Moreover, the encapsulation of oleoresin helps to reduce oxidation process by exposure to the environment, increasing the shelf life and the solubility. The results of analysis of this work lead to the use of bioactive components for implementation in similar products, thereby improving their stability.

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Cristóvão Colombo, 2265, 15054-000 São José do Rio Preto-SP Recebido em 27/4/04; aceito em 21/3/05; publicado na web em 11/7/05 PHYSICO-CHEMICAL ALTERATIONS OF SUNFLOWER, CORN AND SOYBEAN OILS IN DEEP FAT FRYING. The aim of this study is to determine the influence of frying time on the alterations of sunflower, corn and soybean oils during deep fat frying of potato chips. The analytical methods used to evaluate the oil alterations are: free fatty acids, peroxide value, refractive index and total polar compounds. An increase of free fatty acids, refractive index and total polar compounds with frying time were observed. The different behaviors observed for the three vegetables oils can be explained by the differences in the initial composition and quality of them.Keywords: discontinuous frying; vegetable oils; total polar compounds. INTRODUÇÃODurante o processo de fritura, óleos e gorduras estão expostos à ação de três agentes que contribuem para diminuir sua qualidade e modificar sua estrutura: a umidade proveniente dos alimentos, que é a causa da alteração hidrolítica; o oxigênio do ar, que entra na massa de óleo através da superfície do recipiente possibilitando a alteração oxidativa e, finalmente, a elevada temperatura em que ocorre a operação, por volta de 180 o C, que provoca a alteração térmica 1,2 . O mecanismo das alterações termoxidativas e hidrolíticas de um óleo usado para fritura é complexo, pois depende de uma série de parâmetros, tais como tipo de óleo, tempo e temperatura de fritura, relação superfície/volume do óleo, tipo de aquecimento e natureza do alimento a ser frito. A degradação durante um processo de fritura será tanto maior quanto mais prolongado for o período de utilização do óleo e/ou da gordura e quanto maior for sua insaturação 3,4 . Além da insaturação, a qualidade inicial do óleo resultante de efeitos do processamento (temperaturas, adição de ácido cítrico, agentes antiespumantes), assim como a presença de componentes menores e antioxidantes naturais, são fatores importantes na estabilidade dos meios de fritura 2,5 . A crescente utilização de óleos comestíveis para preparação de produtos fritos tem levado a um controle mais rigoroso dos óleos de fritura, uma vez que óleos e gorduras aquecidos e altamente oxidados podem apresentar substâncias potencialmente tóxicas 6 . Entre os principais riscos à saúde envolvidos no consumo dessas substâncias pode-se citar a pré-disposição à arteriosclerose e a ação mutagênica ou carcinogênica 7 . A avaliação da alteração e a identificação dos compostos que são formados durante a fritura de alimentos é de grande importância e interesse, não só para pesquisadores, como também para consumidores, indústrias de alimentos e serviços de inspeção sanitária 8 . Métodos analíticos simples têm sido utilizados para medir as alterações ocorridas em óleos e gorduras de fritura, uma vez que apresentam como característica a realização analítica fácil e rápi-da, não exigindo equipamentos custosos ou de difícil manuseio. Levando em consideração o exposto, alguns valo...