Microencapsulation of bioactive compounds from byproducts of food industry

Предмет истраживања ове докторске дисертације била је микроинкапсулација биоактивних једињења екстрахованих из споредних производа прехрамбене индустрије у циљу њихове стабилизације и побољшања нутритивних својстава. Основне сировине за екстракцију биоактивних једињења, првенствено антоцијана, представљали су покожица црних сорти грожђа и семењача црне соје. Микроинкапсулати екстраката биоактивних једињења су добијени коришћењем три носача: малтодекстрина, арапске гуме и млека у праху, уз примену спреј сушења и лиофилизације као техника инкапсулације комерцијално примењивих у прехрамбеној индустрији. Процес екстракције биоактивних једињења, која су представљала активну компоненту микроинкапсулата, оптимизован је у погледу различитих третмана, времена екстракције, ефикасности растварача, односа чврсте и течне фазе и примене ултразвука различите фреквенције. Оптимизованим течним екстрактима је одређен садржај укупних фенолних једињења, укупних и индивидуалних антоцијана, макроелемената и елемената у траговима. Поред тога, дефинисана им је боја, као и њена стабилност. Такође, испитани су антиоксидативни капацитет, као и антимикробна активност екстраката биоактивних једињења на следеће патогене микроорганизме: Listeria monocytogenes, Bacillus spizizeni, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Yersinia enterocolitica, Escherichia coli O157:H7 и Candida albicans. Основни циљ истраживања је био добијање микроинкапсулата у форми која је најприхватљивија за употребу у прехрамбеној индустрији. Испитиван је ефекат коришћених носача на ефикасност микроинкапсулације екстраката биоактивних једињења у зависности од примењене технике инкапсулације, као и на физичко- хемијска својства микроинкапсулата.The subject of this doctoral thesis was the microencapsulation of bioactive compounds from byproducts of food industry. The raw materials for the extraction of bioactive compounds were the skins of red grape varieties and the coats of black soybean as byproducts of the grape and soybean processing. Microencapsulates were obtained using different carriers such as maltodextrin, gum Arabic and skimmed milk powder, and spray and freeze drying as encapsulation techniques widely used in the food sector. The extraction process was optimized in terms of time of extraction, solvent efficiency, and addition of enzymes, acids, ethanol, solid/liquid ratio, as well as application of ultrasound with different frequencies. Optimized liquid extracts were analyzed by the content of total phenols, total and individual anthocyanins, macro- and rare elements. In addition, the extracts’colour and its stability were defined. Also, their antoxidant capacity and antimicrobial activities against growth of several pathogenic microorganisms (Listeria monocytogenes, Bacillus spizizeni, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Yersinia enterocolitica, Escherichia coli O157:H7 и Candida albicans) were confirmed. The aim of the research was to obtain a microencapsulation in the form that is the most accessible for the application in the food industry. The effects of applied carriers and techniques on the microencapsulation efficiency and physico-chemical properties of microencapsulates were examined. Morphology, thermal analysis, water activity, bulk and tapped density, compressibility, total phenol content, total and individual anthocyanin contents, release of active compounds from microencapsulates in different mediums, colour stability during storage, antioxidant capacity and antimicrobial activity against growth of above-mentioned patogenic bacteria and yeast. Food products with addition of microencapsulates as natural food colours were evaluated..

Raspberry and blackberry pomaces as potential sources of bioactive compounds

Introduction. The concern for obtaining some secondary metabolites with health-beneficial effects has initiated studies on valorization of by-products. In this sense, fruit processing by-products have attracted great interest as sources of bioactive compounds. Materials and methods. Pomaces of rasnberry and blackberry were obtained after juice separation. These byproducts were characterized in terms of total phenolic content (TPC) by Folin-Ciocalteu method and total monomeric anthocyanins content (TAC) by pH differential method. Also, antioxidant activity of pomaces against stable 1,1-dipheny1-2-picrylhydrazyl (DPPH) radicals was evaluated. Results and discussion. Pomace of blackberry was characterized by significantly higher TPC (10.1 mgGAE/g) and TAC (6 mg C3GE/g) compared to raspberry (8.2 and 3.6 mg/g, respectively). DPPH radical scavenging activity was similar, with slightly higher values in pomace of raspberry (11.7 mu molTrolox/g) than in blackberry (10.9 mu molTrolox/g). The total soluble solids was 9.3 degrees Bx in RP sample, significantly lower than in BP sample with value 14.5 degrees Bx. This study indicates that both, raspberry and blackberry pomaces, as wastes of juice production, could be used as a cheap source of bioactive compounds with strong antioxidant activity. Therefore, these pomaces should be considered as a raw material for production of valuable dietary supplements and natural colorants for development of new products with high value added. By-products of fruit processing could be used due to convenience, accessibility and low cost, as suitable way to increase health properties of food. The potential utilization of fruit pomaces could be the enrichment of different products such as bakery products, biscuits, cookies, paste, ice cream, fruit yogurts etc. Additionally, the potential applications of the ethanol used for bioactive compounds extraction in this study must be considered on the basis of the solvent percent choice, liquid-solid ratio, temperature, and time applied. Conclusion. Raspberry and blackberry pomaces, discarded during juice production, represent significant sources of bioactive compounds, such as phenolic antioxidants

An overview of encapsulation technologies for food applications

Encapsulation is a process to entrap active agents within a carrier material and it is a useful tool to improve delivery of bioactive molecules and living cells into foods. Materials used for design of protective shell of encapsulates must be food-grade, biodegradable and able to form a barrier between the internal phase and its surroundings. Among all materials, the most widely used for encapsulation in food applications are polysaccharides. Proteins and lipids are also appropriate for encapsulation. Spray drying is the most extensively applied encapsulation technique in the food industry because it is flexible, continuous, but more important an economical operation. Most of encapsulates are spray-dried ones, rest of them are prepared by spray-chilling, freeze-drying, melt extrusion and melt injection. Molecular inclusion in cyclodextrins and liposomal vesicles are more expensive technologies, and therefore, less exploited. There are number of reasons why to employ an encapsulation technology and this paper reviews some of them. For example, this technology may provide barriers between sensitive bioactive materials and the environment, and thus, to allow taste and aroma differentiation, mask bad tasting or smelling, stabilize food ingredients or increase their bioavailability. One of the most important reasons for encapsulation of active ingredients is to provide improved stability in final products and during processing. Another benefit of encapsulation is less evaporation and degradation of volatile actives, such as aroma. Furthermore, encapsulation is used to mask unpleasant feelings during eating, such as bitter taste and astringency of polyphenols. Also, another goal of employing encapsulation is to prevent reaction with other components in food products such as oxygen or water. In addition to the above, encapsulation may be used to immobilize cells or enzymes in food processing applications, such as fermentation process and metabolite production processes. There is an increasing demand to find suitable solutions that provide high productivity and, at the same time, satisfy an adequate quality of the final food products. This paper aims to provide a short overview of commonly used processes to encapsulate food actives

Inkapsulacija bioaktivnih jedinjenja sporednih proizvoda prerade voća

An increased environmental awareness has led to new trends in food industry, which are reflected in intensive studies on exploitation of fruit processing byproducts. Additionally, consumers' tendency to a healthy lifestyle has initiated the development of diverse functional food products. High amounts of by-products, such as peels, seeds, and stones, are discarded during fruit processing. It represents a problem both from the environmental and the economic point of view. On the other hand, the resulting residues are potential sources of numerous bioactive compounds. Therefore, fruit processing by-products such as substrates for the extraction of phenolic compounds, natural pigments, dietary fibers, protein isolates and oils attract great interest. These extracts have a great potential for the development of dietary supplements and new functional food products with beneficial health effects. However, bioactive compounds are susceptible to degradation, which represents a critical factor for their successful incorporation into food products. In this regard, the main challenge is to ensure the stability of bioactive compounds during processing, storage and in the gastrointestinal tract, i.e. to preserve their bioactivity and bioavailability. This challenge could be accomplished by the use of encapsulation. Namely, the formation of a physical barrier between an active compound and its surrounding is an effective way of protection. The present paper indicates the potential of by-products originating from the processing of apples, grapes, plums, raspberries and sour cherries as sources of bioactive compounds. It also points out the benefits that could be achieved by the encapsulation of bioactive compounds extracted from fruit processing by-products in order to develop new functional food products.Svest o očuvanju životne sredine dovela je do novih trendova u prehrambenoj industriji, koji se između ostalog ogledaju i u intenzivnom izučavanju potencijala iskorišćenja otpada nastalog pri proizvodnji hrane. Pored toga, težnja ka zdravom načinu života doprinela je razvoju funkcionalnih prehrambenih proizvoda. Tokom prerade voća mnogi delovi ploda, kao što su pokožica, semenke i koštice, zaostaju, što predstavlja problem sa ekološkog i ekonomskog aspekta. S druge strane, ovi ostaci predstavljaju potencijalne izvore bioaktivnih jedinjenja. U tom pogledu, nastali sporedni proizvodi prerade voća se intenzivno izučavaju kao sirovine za ekstrakciju fenolnih jedinjenja, prirodnih pigmenata, dijetetskih vlakana, proteinskih izolata i ulja, kao i za proizvodnju suplemenata sa potencijalnim zdravstvenim benefitima. Ipak, kritičan faktor uspešne implementacije ekstrakata bogatih bioaktivnim jedinjenjima u prehrambene proizvode jeste njihova podložnost degradaciji. Prema tome, kao glavni izazov nameće se postizanje stabilnosti bioaktivnih jedinjenja tokom prerade i skladištenja, odnosno očuvanje njihove bioaktivnosti i biodostupnosti. Odgovor na postavljeni izazov očuvanja bioaktivnosti sastojaka hrane može da ponudi inkapsulacija. Naime, inkapsulacija se bazira na formiranju fizičke barijere između bioaktivnih jedinjenja i različitih neželjenih faktora sredine, kao što su visoka temperatura, svetlost, itd. U ovom radu ukazano je na potencijal sporednih proizvoda prerade jabuka, grožđa, šljiva, malina i višanja kao izvora bioaktivnih jedinjenja. Takođe, prikazane su prednosti koje se postižu inkapsulacijom bioaktivnih jedinjenja ekstrahovanih iz sporednih proizvoda prerade voća u cilju razvoja novih, funkcionalnih proizvoda

Assessment of Chemical and Antioxidant Properties of Fresh and Dried Rosehip (Rosa canina L.)

This work aimed to evaluate the nutritional and functional properties of rosehip from Serbia. In respect to that, the content of twenty-three elements in the rosehip along with the soil were determined by inductively coupled plasma-optical emission spectroscopy and the bioaccumulation factor (BAF) was calculated. The total dry matter, water activity, and the contents of vitamin C, total phenolics and flavonoids were determined. The antioxidant ability of fresh and dried samples was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. The obtained extracts were analyzed by gas chromatography with flame ionization detection and gas chromatography - mass spectrometry techniques. In addition, assessment of the impact of thermal treatment on the chemical composition of rosehip was observed. The study revealed that the most abundant elements in rosehip were K, Ca, Mg, P and S with 2963.0, 1820.0, 709.0, 495.0 and 289.8 mg/kg, respectively. The highest BAF values in the system rosehip/soil were for S, K and P. Contents of ascorbic acid, total phenolics, total flavonoids and the antioxidant activity were reduced after the drying process by 56.3%, 20.4%, 31.3%, 21.9%, respectively. Nevertheless, dried rosehip was still a rich source of bioactive compounds with significant antioxidant activity. The presented results support traditional use of rosehip as food with health and nutritional benefits

Application of gum Arabic in the production of spray-dried chokeberry polyphenols, microparticles characterisation and in vitro digestion method

Due to its high content of phenolics, black chokeberry has been proposed as a health-promoting material, especially use of chokeberry extract as a food or pharmaceuticals. Chokeberry extract was spray-dried using gum Arabic as a carrier. The optimal conditions for the efficient microencapsulation of chokeberry extract using spray-drying technique have been investigated. The aim of our study was to obtain microparticles with the best potential to improve functionality and stability of extracted chokeberry polyphenols, and to investigate the possibility of microbeads to protect active compounds during simulated digestion process. Morphological characteristics of microbeads were analyzed using FTIR and SEM techniques. Zeta potential, particle size and moisture content were determined. Released total phenolics and total anthocyanins content as well as concentration of individual anthocyanins were quantified before and after digestion process. Microparticles exhibited high encapsulation efficiency up to 87%, and high content of released polyphenols was achieved. After in vitro simulated digestion phenolic compounds decreased by 11-24%, exhibited higher protective effect of gum Arabic. Our results showed that chokeberry microparticles obtained by spray drying method could be useful supplements or functional food.

Characterization, Antioxidant and Antibacterial Activity of Essential Oils and Their Encapsulation into Biodegradable Material Followed by Freeze Drying

The study assessed the antimicrobial and antioxidant activities of commonly used and commercially available essential oils as an alternative to synthetic preservatives. The plant sources were as follows: lavender (Lavandula angustifolia), tea tree (Melaleuca alternifolia), bergamot (Citrus bergamia) and peppermint (Mentha piperita). The antioxidant activity of essential oils was tested by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods. The microdilution broth susceptibility assay revealed that lavender and bergamot essential oils were more efficient in inhibiting the bacterial growth than other tested oils, with the minimum inhibitory concentration of 5 mu g/mL. This study also reports the successful implementation of an electrostatic extrusion technique for encapsulating essential oils into alginate beads, which enables the essential oils to maintain their free radical scavenging ability over time

Technological Properties of Model System Beef Emulsions with Encapsulated Pumpkin Seed Oil and Shell Powder

The aim of this research was to examine the technological properties of beef emulsions in which fatty tissue was partially substituted with pumpkin seed oil (PSO) encapsulated in alginate or pectin matrix, and where phosphates (F treatments) were simultaneously substituted with shell powder (C treatments). Fat replacement (in the amount of 25%) mostly had no significant influence on pH, cooking loss, purge loss, fluid release under pressure, residual nitrite level, and texture properties. On the other hand, higher yellowness and hue angle were observed when backfat was replaced with encapsulated PSO, but only in treatments with phosphates. The use of shell powder as a phosphate replacer led to significantly higher pH values and thus to significantly higher residual nitrite level: 70.87-74.64 mg/kg (C treatments) is. 56.79-62.16 mg/kg (F treatments). The nitrite depletion rate during the seven-week storage was lower in C treatments. Moreover. higher lightness, yellowness and hue angle could be expected, as well as lower hardness, springiness, cohesiveness and chewiness. For the most part, seven-week storage had no influence on the observed technological properties, except on colour properties in which an opposite trend was observed in terms of yellowness - increase in treatments with phosphates and decrease in treatments with shell powder. Further research, which would include sensory analysis, should be conducted to determine how these altered colour and textural properties will be perceived by consumers

Maltose-mediated, long-term stabilization of freeze- and spray-dried forms of bovine and porcine hemoglobin

Slaughterhouse blood represents a valuable source of hemoglobin, which can be used in the production of heme-iron based supplements for the prevention/treatment of iron-deficiency anemia. In order to obtain a stable solid-state formulation, the effect of maltose addition (30 %) on the stability and storage of bovine and porcine hemoglobin in powders obtained by spray-and freeze-drying (without maltose: Hb; with maltose: HbM) were investigated. Differential scanning calorimetry of spray- and freeze-dried powders indicated satisfying quality of the formulation prepared with maltose on dissolving back into solution. After two-year storage at room temperature (20 +/- 5 degrees C) in solid forms, protected from moisture and light, rehydrated spray- and freeze- dried HbM were red, while Hb were brown. Dynamic light scattering showed the presence of native hemoglobin monomers in rehydrated spray- and freeze- dried HbM, but their agglomerates in Hb samples. UV-Vis spectrophotometry confirmed an absence of significant hemoglobin denaturation and methemoglobin formation in HbM freeze-dried powders. In spray-dried HbM, an increased level of methemoglobin was detected. The results confirmed the stabilizing effect of maltose, and suggested its use in the production of long-term stable solid-state formulations of hemoglobin, along with drying processes optimization

Bioavailability and Bioactivity of Encapsulated Phenolics and Carotenoids Isolated from Red Pepper Waste

In order to deactivate the health properties of bioactive compounds, they need to withstand the effects of food processing, their potential release from the food matrix, and remain bio-accessible in the gastrointestinal tract. Bio-actives from different plants are prone to oxidative degradation, and encapsulation is an effective method in improving their stability. In the present study, red pepper waste (RPW), a by-product of vegetable processing industry, was encapsulated in whey protein using spray and freeze-drying techniques. The aim was to evaluate the effects of in vitro gastrointestinal digestion on the release and bioactivity of encapsulated bio-actives, after each digestion step. The results showed that the release of phenolics and carotenoids, as well as antioxidants, anti-hyperglycemic, and anti-inflammatory activities are influenced by pH and intestinal fluid, with pH 7.5 exhibited at higher levels. There was a rapid initial release of carotenoids from whey protein matrices, while a more gradual increase of phenolics was observed, reaching around 50% for both encapsulates first at 6 h and 37 degrees C, and small intestine conditions. The encapsulation of RPW demonstrated a protective effect against pH changes and enzymatic activities along digestion, and contributed to the increase in bio-accessibility in the gut. Also, the results suggest that encapsulation is an efficient method for valorization of bio-actives from RPW, with improvements in nutrition, color, and bioactive properties