Cristhiane Caroline Ferrari

Effects of Spray-Drying Conditions on the Physicochemical Properties of Blackberry Powder

The purpose of this work was to study the effects of spray-drying conditions on the physicochemical characteristics of blackberry powder using a central composite rotatable design. Inlet air temperature (140–180°C) and maltodextrin concentration (5–25%) were employed as independent variables. Moisture content, hygroscopicity, anthocyanin retention, color, powder morphology, and particle size were analyzed. A higher inlet air temperature significantly increased the hygroscopicity of the powder, decreased its moisture content, and led to the formation of larger particles with smooth surfaces. Powders produced with higher maltodextrin concentrations were less hygroscopic, slightly lighter and less red, and had a lower moisture content. Anthocyanin retention was mainly affected by drying temperature due to the heat sensitivity of the pigment. The optimal processing conditions were an inlet air temperature of 140–150°C and maltodextrin concentration of 5–7%. Overall, these results indicate that good quality powders can be obtained by spray drying, with potential applications for the food industry.

Storage Stability of Spray-Dried Blackberry Powder Produced with Maltodextrin or Gum Arabic

The aim of this work was to evaluate the stability of anthocyanins and antioxidant activity of blackberry powder, obtained by spray drying, using maltodextrin, gum arabic, or a blend of both carrier agents over a period of 5 months. The inlet air temperature was 145°C and the concentration of carrier agent was 7% (w/w). Samples were stored at 25 or 35°C and at relative humidity of 32.8%. Anthocyanin degradation followed the first-order kinetic model. Temperature negatively influenced the stability of anthocyanins, because these pigments are highly thermosensitive. Antioxidant activity increased for the powders stored at 35°C, probably due to the occurrence of the Maillard reaction, leading to the formation of compounds with antioxidant activity. In general, maltodextrin provided greater stability for spray-dried blackberry powder, because particles produced with this carrier agent showed the longest half-life and the lowest anthocyanin degradation rate at 25°C. The use of maltodextrin or the combination of both carrier agents promoted better maintenance of antioxidant potential of blackberry powder. With regard to morphology, all of the samples exhibited a large number of irregular particles with spherical shapes, but powders produced with gum arabic presented the smallest size and shriveled surfaces, which probably affected their stability, resulting in faster anthocyanin degradation during storage.

Kinetic Aspects, Texture, and Color Evaluation of Some Tropical Fruits during Osmotic Dehydration

ABSTRACT Osmotic dehydration of some tropical fruits like guava, melon, and papaya using sucrose and maltose solutions is presented in this article. The influence of sugar type and concentration, process temperature, and calcium salt addition on osmotic solution was investigated. Water loss and sugar gain up to 6 h of processing were evaluated and the effect of osmotic dehydration on fruit quality parameters like color and texture was analyzed. All studied variables affected the osmotic process kinetics, while for quality parameters the influence of sugar type or solution concentration and temperature was dependent on fruit and process conditions.

Cinética de transferência de massa de melão desidratado osmoticamente em soluções de sacarose e maltose

Cubos de melao de 20mm da variedade Cucumis melo inodorus, cultivar Gold Mine foram desidratados osmoticamente com o objetivo de se estudar a cinetica de transferencia de massa durante o processo. As amostras foram imersas em solucoes hipertonicas de sacarose ou maltose nas concentracoes de 40 a 60°Brix e a desidratacao foi conduzida por 8 horas com temperatura controlada (30 ou 40°C) e agitacao de 120rpm. Perda de agua e incorporacao de solidos na fruta foram avaliados ao longo do processo em funcao da temperatura de tratamento, tipo e concentracao da solucao. Os coeficientes de difusao para a agua e os acucares foram estimados atraves de um modelo empirico da literatura, baseado na equacao de Fick. Para todos os ensaios, a perda de agua aumentou significativamente com a elevacao da temperatura e da concentracao da solucao desidratante, entretanto, os ensaios com maltose promoveram uma maior taxa de saida de agua da fruta e menor ganho de solidos. O modelo empirico utilizado se ajustou adequadamente aos dados experimentais, apresentando valores do coeficiente de correlacao (R2) superiores a 0,92.

Secagem por atomização de polpa de amora-preta usando maltodextrina como agente carreador

The aim of this work was to evaluate the influence of inlet air temperature (160 or 180 oC) and maltodextrin concentration (5, 15 or 25%) on the physicochemical characteristics of powdered blackberry juice produced by spray drying. The final product was analysed with respect to moisture content, hygroscopicity, water activity, anthocyanin content, colour, particle size distribution and microstructure. Higher inlet air temperatures resulted in decreases in moisture content, water activity and anthocyanin retention, besides the formation of larger sized, more hygroscopic particles. Temperature only showed a significant effect on the reduction of the L* and C* values for treatments carried out with 25% maltodextrin concentration. Regarding the microstructure, particles produced at 180 oC showed smooth surfaces and a greater degree of uniformity in comparison with samples spray dried at 160 oC. An increase in maltodextrin concentration promoted the production of less hygroscopic particles with lower moisture content. Furthermore, these powders showed lower anthocyanin contents, due to dilution of the fruit pigments, leading to an increase in the L* values and reduction in the chroma and hue angle values. The treatment carried out at 160 oC with 5% maltodextrin was the most effective in maintaining the anthocyanin content of the powder, with a pigment retention of about 80%.

Structural Changes, Mechanical Properties and Sensory Preference of Osmodehydrated Melon Pieces with Sucrose and Calcium Lactate Solutions

The effect of calcium lactate on the cellular structure and mechanical properties of osmodehydrated melon pieces with sucrose solutions was studied. Samples were treated with sucrose solutions (40 or 60°Brix) containing calcium lactate (0 to 20 g kg−1). The salt had a remarkable effect on the stress at failure and the cellular structure of fruits, resulting in structural preservation when used at concentrations of up to 10 g kg−1. Salt concentrations above 15 g kg−1 as well as the treatment performed with sucrose solution alone promoted cytoplasm plasmolysis and cell wall damages. Fruits processed with sucrose solutions at 60°Brix with or without calcium lactate showed good sensory acceptance, while fruits treated with sucrose solutions at 40°Brix presented statistically significant lower scores at calcium concentrations above 15 g kg−1.

Influence of Processing Additives on the Quality and Stability of Dried Papaya Obtained by Osmotic Dehydration and Conventional Air Drying

The combination of osmotic dehydration and hot air drying (OD/HA) is an industrial alternative to papaya production, but tissue softening and color loss are technological problems. The objective of this work was to study, during OD/HA processing of papaya (Formosa cultivar), the influence of organic acids (citric and lactic), calcium salts (lactate and chloride), and the enzyme pectinmethylesterase (PME) on the texture, color, and sensory characteristics of the product. The stability of the products treated with lactic acid/calcium chloride, PME/calcium chloride, and the standard sample (without additives) was evaluated at 25 and 35°C for up to 100 days, analyzing vitamin C and color degradation. Light microscopy analysis performed at the beginning of stability study showed that the additives better preserved the cell structure. The use of lactic acid/calcium chloride maintained the color of the dried papaya, but the additives did not have an effect on vitamin C degradation. The variations in the chromaticity parameters (b* and a*) were adjusted to zero- and first-order kinetic models, respectively, with Q 10 values ranging between 0.88 and 2.30 and R 2 ∼ 0.90. The combination of lactic acid/calcium chloride resulted in higher sensory acceptance and color stability of dried papaya during storage.

Vida útil de fatias de manga armazenadas em embalagem com atmosfera modificada passiva

Fresh and osmodehydrated mango slices were packaged in expanded polystyrene trays covered with low density polyethylene films (PEBD) and stored at 5 °C aiming at verifying the effect of osmotic dehydration process and modified atmosphere packaging on the fruit shelf life. Fresh mango slices packaged under atmospheric conditions were used as control. The slices were evaluated periodically with respect to physicochemichal and microbiological characteristics, internal atmosphere composition of the packages, weight reduction, and sensory acceptance. The osmotic dehydration process and the modified atmosphere packaging had a positive influence on the preservation of the sensory characteristics and microbiological quality of the mango slices. Fresh mango slices stored under atmospheric conditions (FR AR) and modified atmosphere packaging (FR MAP) had a shelf life of only 8 and 14 days, respectively, which was mainly limited by its sensory acceptance and microbial spoilage. On the other hand, the mango osmodehydrated slices packaged under modified atmosphere (OD MAP) presented shelf life of 18 days showing good sensory acceptance throughout the storage period.

Calcium lactate effect on the shelf life of osmotically dehydrated guavas.

The effect of calcium lactate on osmodehydrated guavas in sucrose and maltose solutions was monitored during storage under passive modified atmosphere for 24 d at 5 °C. Sample texture and color characteristics, microbial spoilage, sensory acceptance, structural changes, and gas composition inside the packages were periodically evaluated. Calcium lactate inhibited microbial growth on guavas, with yeast and mold counts in the order of 10(2) CFU/g throughout storage. The calcium salt reduced respiration rate of guava products, showing O(2) and CO(2) concentrations around 18% and 3% inside the packages. A firming effect on fruit texture, with up to 5 and 2 times higher stress and strain at failure values and tissue structure preservation could also be attributed to calcium lactate use. However, fruits treated with calcium lactate, osmodehydrated in maltose and sucrose solutions, showed sensory acceptance scores below the acceptability limit (4.5) after 13 and 17 d of storage, respectively.

Performance of different process additives on the properties of mango powder obtained by drum drying

ABSTRACT The use of process additives was evaluated in the drum drying of commercial mango pulp, using corn starch, maltodextrin 10/20 DE, and glyceryl monostearate (GMS). The mass flow rate (MFR) and some powder properties were analyzed: moisture content, vitamin C, total phenolic compounds, carotenoids, β-carotene, glass transition temperature (Tg), hygroscopicity, solubility, color, rheological behavior and color of reconstituted pulp. The pulps presented non-Newtonian and pseudoplastic fluid behavior, while Tg values ranged from 29°C to 38°C. The process performed with 3% corn starch and 0.5% GMS (dry basis) resulted in greater MFR (8.0 ± 0.2 kg/h m2) and vitamin C retention (61.0 ± 0.7%).