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Resistant starch (RS) is a part of insoluble dietary fiber, and it could be recognized as a functional food ingredient in some types of confectionery products that lack dietary fiber. Unlike dark and milk chocolate, white chocolate does not contain fat-free cocoa solids rich in dietary fiber. In the present study, 5%, 10%, and 15% of white chocolate were substituted with RS in order to improve the nutritional value of enriched white chocolate. The influence of RS on rheological, textural, and thermal properties of the chocolate fat phase was firstly investigated, and then further influence on physical properties, dietary fiber content, and sensory characteristics of enriched white chocolates were investigated. The obtained results showed that enriched chocolates had increased content of total dietary fiber and reduced total fats and protein content in accordance with the added amount of RS. At the same time, RS increased viscosity and reduced the hardness and volume mean diameter in enriched chocolates in accordance with the added amount. RS improved the nutritional composition of white chocolate by increasing the content of dietary fiber. At the same time, RS did not impair the color and sensory characteristics of enriched white chocolates.

Pasta is one of the most popular meals in the world. It is affordable, easy to combine with other foods and easy to cook. Unfortunately, pasta is energy-rich and nutrient-poor. Whole-wheat pasta is somewhat better in nutritional quality, but further improvements may be made. One option is to add different raw materials and specific nutritive components (vitamins, polyphenols, fiber, protein, etc.) to semolina. However, this approach changes its physico-chemical properties, e.g. cooking loss, texture, etc., which cannot be disregarded. The current research investigates possibilities for production of barley-enriched pasta with acceptable cooking qualities. To ensure the beneficial health effects of β-glucan, β-glucan-rich barley was selected asa starting material. Pasta enriched with 10–50% β-glucan-rich barley flour was produced in the mini-press and the laboratory extruder and then dried at low, medium and high temperature regimes. Colour, cooking quality and microstructure of the enriched pasta were investigated to determine its acceptability. The research showed that barley-enriched pasta of good cooking quality might be produced by selecting an optimal combination of suitable production parameters for forming and drying.

The addition of brewer’s spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP), on the nutritional properties of directly expanded snack products based on corn grits was investigated. Snack products were produced in a laboratory single screw extruder with the addition of 5, 10 and 15% d. m. of these by-products in corn grits. Chemical composition, total phenolic content, antioxidant activity, dietary fiber, resistant starch, starch damage and pasting properties of the mixtures and extruded samples were determined. Extrusion process and by-product additions had a significant effect on the proximate chemical composition. All three by-products increased contents of both soluble and insoluble dietary fiber, while the extrusion caused a reduction of insoluble fiber and increase of soluble fiber. After the extrusion process starch damage and antioxidant activity increased, while resistant starch content and total polyphenol content decreased. According to obtained results, it can be concluded that the investigated by-products can be used in the production of nutritionally more valuable corn snacks.

Recently, the enrichment of chocolate has become a very interesting topic, along with the management of food industry by-products, such as cocoa shells. Cocoa shells could be a great raw material for the cocoa industry, both for economical reasons (maximized utilization of cocoa beans) and for their functional properties (increased fiber content). In this research, we used untreated and high-voltage electrical discharge (HVED)-treated cocoa shells in the production of chocolate. Different proportions of cocoa mass were replaced with cocoa shells to produce dark and milk chocolates in a ball mill. Additionally, dark chocolate with 15% and milk chocolate with 5% of shells were chosen for further research and to study the alteration of the composition. The rheology, particle size distribution, hardness, and color were determined for all the prepared samples. Treated cocoa shells provided chocolates with inferior physical properties compared to chocolates with untreated shells. Therefore, untreated cocoa shells were selected for further analysis. The addition of both treated and untreated cocoa shells resulted in softening and darkening of samples, which could have a positive effect for consumers. On the other hand, the particle size distribution and rheology were negatively affected. Further research is needed to find a solution for these problems.

The objective of this research was to investigate the potentiality of carrot powder (CP) utilization at levels 4, 6, or 8% as ingredient of corn snacks and evaluation of the extrusion influence on functionally important ingredients such as carotenoids (color), polyphenols, fiber, fat, and antioxidant activity. The influence of ascorbic acid (AA) as an external source at levels 0.5 and 1% on this particular extrusion was also investigated. A single-screw extruder at two temperature regimes (135/170/170 °C (E1) and 100/150/150 °C (E2)) carried out extrusion. The E1 temperature regime acted favorably on total polyphenol content and crude fiber, but fat preferred the E2 regime. Extrusion, especially the E1 temperature regime, increased the extractability of carotenoids. Ascorbic acid degraded during extrusion, but it still provided protection to carotenoids and color attributes of extrudates. Snacks with increased nutritional and functional value due to carrot powder addition were successfully produced, which is a starting point for production of a new type of extruded snacks.

Chocolate is a product that has a high content of fat and sugar. The addition of fibers and polyphenols in chocolate is increasingly being applied and studied in recent years. Since chocolate is a food product that has sensitive rheological properties, any addition of components that are not part of the standard recipe may have a significant influence on physical, chemical and sensory properties. Although cocoa is rich in polyphenols, their share in chocolate depends on the share of cocoa parts and the parameters during processing. Nutritional value of chocolate may be improved by addition of additional sources of nutritious compounds. This paper gives an overview of recent research regarding addition of fiber and polyphenols to chocolate.

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber, however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters, however, additional research is needed to reveal exact mechanisms and implications.

Cocoa shell is a by-product of the chocolate industry that is rich in dietary fiber and bioactive components. In this research, the influence of high voltage electric discharge (HVED) treatment on chemical and physical characteristics of the cocoa shell, i.e., the effects of applied time and frequencies on grinding ability, water binding capacity (WBC), dietary fibers and tannin content was investigated. HVED had a significant influence on the chemical and physical properties of cocoa shell, all of which could be linked to changes in fiber properties. Along with the fiber content, grinding ability and water binding capacity were increased. These properties have already been linked to fiber content and soluble/insoluble fiber ratio. However, this research implies that change in fiber properties could be linked to tannin formation via complexation of other polyphenolic components. Additional research is needed to verify this effect and to establish mechanisms of tannin formation induced by HVED and its influence on fiber quantification.

Cocoa shell is one of the by‐products obtained in chocolate industry which was considered as waste for a very long time. Recently, the presence of high‐valuable bioactive components in cocoa shell was recognized, and research on the pallet of food products enriched with cocoa shell is increasing. The most abundant bioactive components of untreated cocoa shell (UCS) are theobromine (3.906 ± 0.070 mg/g), caffeine (0.646 ± 0.055 mg/g), and (+)‐catechin (0.290 ± 0.005 mg/g), followed by gallic acid (0.147 ± 0.041 mg/g) and (−)‐epicatechin (0.165 ± 0.099 mg/g). Furthermore, the impact of concentration (1.5 and 3% of cocoa shell in water), high‐voltage electric discharge (HVED) treatment (40 and 80 Hz), and treatment time (15, 30, and 45 min, respectively) on bioactive compounds content was evaluated. Statistically significant differences between treatment conditions were obtained. Generally, water‐HVED treatment at 40 Hz has lower impact on bioactive components than water, and water‐HVED at 80 Hz, therefore, can have a significant effect on future treatments of materials rich in bioactive compounds. PRACTICAL APPLICATIONS: HVED is an innovative nonthermal processing technique that has mechanical and electrical effect on the product resulting with lower costs and increase of functional properties. This study has shown that HVED causes lower decrease of phenolics and methylxanthines in cocoa shell which can have a significant effect on future treatments of materials rich in bioactive compounds. Because it is not recorded in scientific literature that HVED treatment was used on cocoa shell so far, it will help in future research and applications of cocoa shell in the food industry.

This study aimed to produce starch esters by roasting potato starch with apple distillery wastewater at various temperatures and aimed to determine the effects of esterification conditions on selected properties of the modified preparations. Apple distillery wastewater was concentrated, mixed with starch (30 g of dry matter per 100 g of starch), dried, and roasted at temperatures of 110, 130 or 150 &deg, C for 3 h. The resulting preparations were rinsed 30 times with a 60% ethanol solution, dried, and disintegrated. After that, the following analyses were performed: content of substituted acids (after alkaline de-esterification) with high performance liquid chromatography (HPLC), thermal characteristics with differential scanning calorimetry (DSC), swelling power and solubility in water at 80 &deg, C, color changes with a colorimeter, rheology of the pastes based on the plotted flow curves, and the pastes&rsquo, resistance to amyloglucosidase. Starch treatments with apple distillery wastewater at 130 and 150 &deg, C caused significant changes to its properties when compared to the control samples of native starch and starch roasted without wastewater, including: a lower temperature and heat of pasting, lower swelling power and solubility in water, darker color, higher resistance to amyloglucosidase, and the formation of pastes with a lower viscosity.

Chocolate production is a complex process during which numerous chemical reactions occur. The most important processes, involving most of the reactions important for development of the proper chocolate flavor, are fermentation, drying and roasting of cocoa bean, and chocolate conching. During fermentation, formation of important precursors occurs, which are essential for further chemical reactions in the following processes of chocolate production. Roasting is one of the most important processes due to the occurrence of Maillard’s reactions, during which aroma compounds are formed. In this paper, we have reviewed the most important chemical reactions that occur with proteins, carbohydrates, lipids, and polyphenols. Additionally, we present other components that may be naturally present or form during the production process, such as methylxanthines, aldehydes, esters, ketones, pyrazines, acids, and alcohols.

The aim of this study was to develop a liquid chromatography/tandem mass spectrometry LC-MS/MS method for the simultaneous determination of acrylamide and hydroxymethylfurfural (HMF) in corn snack products enriched with food industry by-products: brewer&rsquo, s spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP). Development of the method included the study of different sources for ionization, different mobile phases, different extraction conditions as well as different methods of sample preparation. Finally, the single LC-MS/MS method was developed for the analysis of both analytes in one step with a duration of 20 min using a simple single-step extraction. The method with apparent recoveries of 91.4 and 90.4 for acrylamide and HMF, respectively, was applied for the analysis of non-extruded and extruded samples. The obtained results shown that the acrylamide content was &lt, LOD (limit of detection) for all raw materials and non-extruded mixtures, while HMF increased proportionally to the content of added by-products in the mixtures. After the extrusion process, quantification of the acrylamide could be done in all samples. A higher amount of by-products entails higher contents of acrylamide and HMF, with the most significant effect in AP extrudates, where the highest content of HMF (6069 &plusmn, 789 ng/g) and acrylamide (5.37 &plusmn, 0.50 ng/g) in samples with 15% AP was observed.

The aim of this research was to enrich extruded snack with cocoa husks. It was added to corn grits in 5%, 10%, and 15% d. m., the moisture was set to 15%, and the prepared samples were extruded in a laboratory single screw extruder at 135/170/170°C, with 4 a mm‐round die and a screw with the compression ratio of 4:1. Physical properties, resistant starch (AOAC 2002.02), starch damage (AACC 76‐31), polyphenol content (Folin‐Ciocalteau), and antioxidant activity (DPPH) were determined. Although the addition of cocoa husk resulted in harder, darker snacks with increased retrogradation tendency, these properties were still in the acceptable range. Resistant starch, polyphenol content and antioxidant activity of the flips increased proportionally with the addition of cocoa husks, while starch damage slightly decreased, indicating that cocoa husk may be successfully employed as an agent for the fortification of nutrients.

Starch is a very common carbohydrate. Along with its use in the pharmaceutical, textile, and paper industries, starch is widely used in the food industry as well, but native starch has limited use due to its certain properties such as retrogradation, problems related to gelatinization, instability at high temperatures, and acidic conditions. Various modification procedures are used to improve the properties of native starch. Along with consumer demands for healthy, minimally processed, and sensibly priced food products, more attention is being paid to nonthermal food friendly technologies that are environmentally friendly and do not severely affect the product. Cold plasma, ultrasound, high pressure, and pulsed electric field as nonthermal methods have little influence on the most important properties of food and thus have significant potential in this regard, as the food produced by nonthermal methods might be more acceptable to consumers. This paper gives an overview of previously mentioned methods in starch modification. PRACTICAL APPLICATIONS: The food industry, at a recent time, has shown a great interest in the development of procedures which enable minimal food processing and getting products with better organoleptic and nutritive properties with little energy loss and shorter technological procedure duration. This paper presents some of the current research and results of nonthermal methods application in the food industry, mainly its application in starch modification and influence on certain starch properties.

In the hazelnut oil production it is very important to find an appropriate method to recover the oil from kernels. The objective of this study was to evaluate the oil extraction process from hazelnuts by screw pressing followed by extraction with supercritical CO2. The effects of temperature head presses, frequency and nozzle size in pressing experiments on oil temperature and recovery were monitored. The optimal pressing condition using response surface methodology was determined. In obtained hazelnut oil the following quality parameters were determined: peroxide value 0 mmol O2/kg, free fatty acids 0.23%, insoluble impurities 0.42%, moisture content 0.045%, iodine value 91.55 g I2/100 g, saponification value 191.46 mg KOH/g and p-anisidine value 0.19. Rosemary extract was the most effective in protecting the oil from oxidative deterioration. The residual oil that remained in the cake after pressing was extracted totally with supercritical CO2 and such defatted cake, free of toxic solvents, can be used further in other processes.

Cabbage is an important source of bioactive compound, which is available throughout the year. However, a lot of different traditional, and hybrid varieties with different levels and composition of bioactive compounds can be found on the market. The aim of the study was to obtain quantitative results showing comparative differences between different white cabbages (&ldquo, Čepinski&rdquo, &ldquo, Varaždinski&rdquo, Bravo&rdquo, Ogulinski&rdquo, ) from Croatia. Morphometric parameters and physicochemical composition were determined while using standard procedures. Phenolic acids were determined using high-performance liquid chromatography and volatile compounds were analysed by the solid-phase micro-extraction gas chromatography with mass spectrometry (SPME-GC-MS) smethod. The results showed that studied cabbage cultivars differed in physicochemical composition and morphological traits. Six phenolic acids were identified and quantified, whereas a sinapic acid was the most dominant component (65.9&ndash, 78.15 mg/kg). Aldehydes, esters, alcohols, and terpenes were the major classes of organic volatile compounds present in the studied cabbages. &ldquo, which has never been analysed before, showed to contain the highest amount of d-limone (40.75 &micro, g/L) and allyl isothiocyanate (1090.26 &micro, g/L), the most important volatile compounds responsible for the fresh cabbage flavour. The presented results mark off &ldquo, cultivar as valuable for larger production and further examination.

The cocoa and chocolate industries have huge problems with the utilization of waste generated during the production process. Waste material generated during production include cocoa pod husk, pulp, and cocoa bean shell. Cocoa shell is a by-product that has great potential because of its composition. It consists of dietary fibers, proteins, polyphenols, methylxanthines, etc. However, despite its favorable composition, cocoa shell often cannot be used directly in food production because it may contain components that are harmful for human health. Cocoa shell can carry mycotoxins, different microorganisms, polycyclic aromatic hydrocarbons, and heavy metals. High voltage electrical discharge presents a novel non-thermal method that has great potential for the decontamination of waste materials and can also be used for extraction of valuable compounds from cocoa shell.

In this study, the effect of encapsulated sour cherry pomace extract on the physical characteristics of the cookie dough (colour, textural and rheological properties) was investigated. Sour cherry pomace extract encapsulated in whey (WE) and soy proteins (SE) was incorporated in cookie dough, replacing 10% (WE10 and SE10) and 15% (WE15 and SE15) of wheat flour. The dough samples containing encapsulates had the grey-blue colour ( b* values significantly decreased compared to control sample). Due to the presence of anthocyanins, a* values of the dough colour increased significantly with the addition of encapsulates. The addition of soy protein encapsulate increased hardness, resistance to extension and viscosity of cookie dough and decreased deformation compliance ( J), while the addition of whey encapsulate caused dough softness, higher deformation compliance and lower values of viscosity compared to control sample. Values of storage and loss modulus, G′ and G″, significantly decreased when wheat flour was replaced with WE and increased when the flour was replaced with soy protein encapsulate. The addition of soy protein encapsulate resulted in higher cookie hardness.

Solving the problem of large quantities of organic waste, which represents an enormous ecological and financial burden for all aspects of the process industry, is a necessity. Therefore, there is an emerged need to find specific solutions to utilize raw materials as efficiently as possible in the production process. The cocoa shell is a valuable by-product obtained from the chocolate industry. It is rich in protein, dietary fiber, and ash, as well as in some other valuable bioactive compounds, such as methylxanthines and phenolics. This paper gives an overview of published results related to the cocoa shell, mostly on important bioactive compounds and possible applications of the cocoa shell in different areas. The cocoa shell, due to its nutritional value and high-value bioactive compounds, could become a desirable raw material in a large spectrum of functional, pharmaceutical, or cosmetic products, as well as in the production of energy or biofuels in the near future.

The aim of this study was to investigate the possibility of application of brewer's spent grain (BSG), sugar beet pulp (SBP) and apple pomace (AP) in production of corn snack products. Additionally, in the case of BSG and SBP the pectin (0.5% and 1% d. m.) was added in an attempt to resolve the problems of poor expansion and textural properties. Samples were extruded in the laboratory single screw extruder, and physical and sensory properties of obtained extrudates were determined. By-products addition decreased expansion ratio and fracturability, whereas bulk density and hardness increased. Pectin addition at level of 1% resolved the problem of poor expansion in the extrudates with BSG and SBP, which resulted in successful incorporation of all three by-products in the production of acceptable expanded corn snack products. By-products addition and extrusion process had a significant effect on color change, water absorption and water solubility indexes. Industrial relevance The production of nutritionally fortified snack products, with the acceptable physical and sensory properties is challenging. The addition of high-fibre and high-protein ingredients to starch based raw materials significantly affects the texture, expansion and overall acceptability of extruded snacks. This study provided a novel and effective way to resolve these problems in production of corn extrudates enriched with food industry by-products, by pectin addition. Furthermore, this investigation could partially help in the disposal of waste from the food industries in which the investigated by-products (brewer's spent grain, sugar beet pulp and apple pomace) are formed in large quantities.

The aim of this research was to investigate the influence of the addition of tomato powder (TP) to corn grits at levels 4, 6 or 8 % and the addition of ascorbic acid (AA) at levels 0.5 and 1 %, on total polyphenol content (PF), and antioxidant activity of the extrudates. The hardness and the expansion ratio of the extruded products were also tested. Mathematical models that describe the influence of additives on the mentioned properties were also determined. Extrusion was performed at two temperature regimes: 135/170/170 °C and 100/150/150 °C. Lower temperature regime led to increased hardness and the expansion of extrudates. The addition of tomato and AA led to decreased hardness and the expansion at both temperature regimes. The addition of tomato increased PF and AA compared with pure corn extrudates. Greater degradation of PF and AA was at lower temperature regime. High correlation between PF and AA was demonstrated at both extrusion temperatures.

Extrusion process is one of the most important innovations of the 20th century applied in many industries. Extrusion is a technology that is increasingly used for the production of various food products, especially snacks and breakfast cereals. Supercritical carbon dioxide (CO2) as a non-toxic, non-flammable and inexpensive, is applied in many processes, including the extrusion technology. Supercritical CO2 extrusion process (SCFX) found its application primarily in the processing and manufacturing plastic, but recently more and more begins to be applied in food production and processing. Scientific researches in this area are based in production of extrudates with improved properties compared to conventional extrusion process without the addition of CO2. A number of applications of SCFX in food processing technology will be reviewed and numerous advantages over the conventional process will be described in this paper.

The effects of defatted hemp cake added to corn grits (in ratios of 0, 5 and 10% d.m.), the moisture content of the mixtures (15, 20, 25%) and the temperature in the extruder ejection zone (150, 165, 180 °C) on the physical properties of extruded products have been investigated. Statistical optimization of investigated extrusion conditions using the response surface methodology was performed. The hemp cake was completely defatted by means of a supercritical CO2 extraction. The extrusion was performed on a laboratory single screw extruder and regulated by the following parameters: temperature in the dosing and compression zone (120 and 150 °C), screw compression ratio (4:1), round die (4 mm). The change of extrusion process conditions has significantly affected the physical properties of produced snacks. The expansion ratio ranged between 1.38 and 3.11, the bulk density between 0.14 and 0.49 g/cm3, the hardness between 18.15 and 70.62 N, the fracturability between 3.65 and 10.38 mm, and the total color change between 3.25 and 24.73.

This study was aimed at investigating the possible application of defatted hazelnut, camelina, pumpkin, and hemp cakes (by-products of edible oil production) in the production of corn snack products, and to use supercritical CO2 as a blowing agent in indirectly expanded snack products. Cakes were added in 3, 6, and 9% proportions. Extrusion was performed in a laboratory single screw extruder and expanded by microwave. The obtained extrudates were evaluated for their physical and sensory properties. For comparison, directly expanded products without supercritical CO2, were produced with the same raw materials. The addition of the by-product had a significant influence on the expansion ratio, bulk density, fracturability, and crispiness, and all four by-products were successfully incorporated in the production of sensory acceptable, indirectly expanded snack products, produced by supercritical fluid extrusion. This type of products is interesting for consumers since it can be home-made and produced without additives or any chemical substances.

Kosovic I., Jukic M., Jozinovic A., Ackar Đ., Koceva Komlenic D. (2016): Influence of chestnut flour ad- dition on quality characteristics of pasta made on extruder and minipress. Czech J. Food Sci., 34: 166-172. Durum semolina was replaced with 10, 15, and 20% of chestnut flour. Pasta was produced on a single screw extruder with the temperature profile of 80/90/90°C and on a laboratory minipress. Pasta samples were dried at room tem - perature and physical and sensory properties were determined. Generally, the chestnut flour addition to durum wheat pasta decreased optimum cooking time, hardness, cohesiveness, and chewiness, but increased cooking losses and pasta adhesiveness. Samples made on an extruder showed shorter optimum cooking times in relation to samples made on a minipress. Absorbed water was decreased with chestnut flour addition. Pasta made on an extruder showed a higher sensory score in comparison with pasta made on a minipress. The addition of chestnut flour influenced the colour of the samples. Samples made on an extruder showed darker colour in dried and cooked pasta samples in relation to minipress samples. In dried pasta samples, the extruder gave yellower samples in relation to the minipress, while in cooked pasta samples it was reversed. Overall, the extruder gave higher-quality pasta compared to the minipress.

Starches were isolated from three oat (Dzoker, Zvolen and Sampionka) and three barley (Barun, Zlatko and Vanessa) cultivars. The gelatinisation and retrogradation characteristics, pasting properties, swelling power, and solubility of the isolated starches were analysed. The gelatinisation onset temperatures varied from 59.4°C to 61.4°C for the oat starches (OS), and from 58.4°C to 62.2°C for the barley starches (BS). BS displayed a higher retrogradation enthalpy (ΔHr) than OS after 7 and 14 days storage at 4°C. OS-Sampionka had the lowest one while BS-Vanessa had the highest ΔHr after 7 and 14 days of storage. Significant differences in pasting properties were observed between the OS and BS. OS showed higher values of maximum viscosity than BS and followed the order: OS-Dzoker > OS-Sampionka > OS-Zvolen > BS-Vanessa > BS-Zlatko > BS-Barun. The breakdown viscosities of BS were considerably lower than those of OS. OS had higher swelling power and solubility values than BS. The higher swelling and solubility values of the oat starches in conjunction with lower retrogradation suggest different applications of these starches. The results showed that, while the barley starches are suitable for such applications where high stability is needed during heating and shearing (low breakdown values), the oat starches have a great potential for the applications where high stability during storage is needed (low ΔHr values). In addition, the barley starches are suitable for those applications where high water binding is undesirable, while the oat starches are applicable where low amounts of starch need to bind high proportions of water.

Colour and texture are very important quality properties of all foods. In this work, the influence was investigated of different types of pectin on colour and textural properties in strawberry jams and low-calorie strawberry jams containing fructose and aspartame or fructose syrup and aspartame. The highest anthocyanin content and total phenol content were detected in strawberry jam samples prepared with low methoxy amidated pectin. During storage, after 4 and 6 weeks at both storage temperatures, room temperature and 4°C, anthocyanin content and total phenol content decreased. Also, free radical scavenging activity decreased during storage. As far as the texture parameters are concerned, namely firmness, consistency and cohesiveness, the highest values were found in strawberry jam samples prepared with high methoxyl pectin.

Starch has been an inexhaustible subject of research for many decades. It is an inexpensive, readily-available material with extensive application in the food and processing industry. Researchers are continually trying to improve its properties by different modification procedures and expand its application. What is mostly applied in this view are their chemical modifications, among which organic acids have recently drawn the greatest attention, particularly with respect to the application of starch in the food industry. Namely, organic acids naturally occur in many edible plants and many of them are generally recognized as safe (GRAS), which make them ideal modification agents for starch intended for the food industry. The aim of this review is to give a short literature overview of the progress made in the research of starch esterification, etherification, cross-linking, and dual modification with organic acids and their derivatives.

The effects of hydrocolloids pectin, carrageenan, as well as of pectin/carrageenan mixtures on gelatinisation, retrogradation, rheological characteristics, and swelling power of tapioca starch were studied with Brookfield rotational viscometer and differential scanning calorimeter (DSC). The results showed that hydrocolloids retarded the retrogradation of tapioca starch. Enthalpy and temperatures of gelatinisation, as well as solubility, did not vary significantly in starch-hydrocolloid systems. Viscosity of tapioca starch increased on the addition of hydrocolloids: the effect of carrageenan on viscosity was more remarkable than that of pectin.