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The relationship between quality attributes and microstructure in strawberry pulp after pasteurization (PS), ultrasound (US), electron beam irradiation (EB), and high pressure (HP) treatments was investigated. The results showed that US treatment decreased the viscosity to the lowest by 80.15% and increased the a* value, cloudy stability, and contents of titratable acid, total soluble solid, organic acids, total phenols, total flavonoids, and total anthocyanins (TAC), as well as its antioxidant capacity, due to the decrease in particle size, the destruction of microstructure, and the release of intracellular compounds. US and EB treatments could maintain the volatile compounds. The greatest deterioration in TAC and volatile compound content was found in the pulp treated with PS and HP treatments. HP treatment was beneficial to the enhancement of apparent viscosity, organic acids, and soluble sugar. These results provided insights into the enhancement of quality attributes in strawberry pulp due to the microstructure change.

To investigate the impact of different ultrasonic power densities (2.7, 4.5, 6.3, and 8.1 W/mL) on the rheological properties of strawberry pulp, the changes in physical properties of the pulp and the physicochemical and structural attributes of three pectin fractions in the pulp, water-soluble pectin (WSP), chelator-soluble pectin (CSP), and Na 2 CO 3 -soluble pectin (NSP) were analyzed. Increased power densities damaged the cell fragments in pulp, leading to a decrease in particle size. The apparent viscosity of the pulp initially increased, but subsequently decreased with further increases in power densities. The molecular weight (Mw) of three pectin fractions decreased with increasing power densities, accompanied by structural disintegration and a gradual reduction in apparent viscosity. However, the proportional changes in the monosaccharide composition between the three pectin fractions after ultrasonic treatment were inconsistent. Subsequent analyses showed that the increase in the apparent viscosity of pulp after ultrasonic treatment was related to the reduction in the particle size. Meanwhile, the decrease in the M W of pectin and the disruption of the pectin structure by ultrasonic treatment led to a decrease in the apparent viscosity of both pectin and pulp. [Display omitted] • The particle size of strawberry pulp decreased with ultrasonic power densities. • Pulp's viscosity increased gradually before rapidly decreasing with power densities. • The structures of pectin were affected and their M w decreased after ultrasound. • The apparent viscosity of three pectin fractions decreased after ultrasound. • Particle size and pectin jointly influenced the rheological properties of pulp. [ABSTRACT FROM AUTHOR]

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The five most widely used mathematical models, which were additionally extended with a dimensionless coefficient (i.e. the drying air temperature), were examined for the best approximation of strawberry pulp convective drying in a thin stagnant layer. Furthermore, the effects of the drying air temperature and ascorbic acid on changes in the color of strawberry pulp during the drying process were examined. The statistical parameters of the mathematical models (namely R, X2 , RMSE) indicated that the Extended Modified Page model had the best fit for the convective drying of strawberry pulp. The changes in the color of the dried control sample, without the addition of ascorbic acid, were ΔE = 22.95 and ΔE = 25.71 at air temperatures of 45 °C and 65 °C, respectively. The greatest change in the sample color (ΔE = 14.66) was observed at an air temperature of 45 °C and an ascorbic acid additive value of 0.5 %. However, the smallest change in the sample color (ΔE = 12.57) was observed at an air temperature of 65 °C with the addition of 1 % ascorbic acid.

The physical property and retention of anthocyanins (ACNs) during digestion of strawberry pulp after high-pressure homogenization (HPH) (20/60/100/140 MPa) were analyzed, and their correlations with the three pectin samples—water-soluble (WSP), chelator-soluble (CSP) and sodium carbonate-soluble (NSP)—were evaluated. Compared to the control, the particle size and apparent viscosity of the pulp decreased, and the retention of total ACNs increased, reaching the highest at 100 MPa, with an increase of 15.41%. After HPH treatment, the alcohol-insoluble residue (AIR) and WSP content increased, while the molecular weight (Mw), and microstructural tightness of the three pectin samples decreased. The homogalacturonan (HG) region of WSP increased, and the degree of methylesterification (DM) of CSP decreased. Furthermore, the important role of the modified pectin in the increased retention of ACNs during digestion was reaffirmed by the binding ratio and retention of ACNs in pectin-ACNs complexes. The effect of HPH treatment on the quality attributes of fruits and vegetable juice attracted a lot of attention. This study confirmed that the modification of pectin in HPH-treated strawberry pulp, which promoted its interaction with ACNs, could effectively enhance the retention of ACNs during digestion. Consequently, this study provides the fundamental theory and technological support for the potential to elevate the nutritional value of fruits and vegetables. • HPH treatment improves the digestive retention of the ACNs. • The apparent viscosity and particle size decreased after HPH treatment. • WSP and CSP have higher binding and retention on ACNs than NSP. • The modified pectin by HPH treatment contributes to the increased retention of ACNs. [ABSTRACT FROM AUTHOR]

Abstract The sensorial evaluation of a prebiotic sheep milk juice beverage considering a consumer's perception was performed. Four beverages with different concentration of skimmed sheep milk, strawberry pulp and sugar, added with a fixed inulin level (3 g/100 g) were manufactured and submitted to hedonic and preference ranking test with 60 consumers. Beverages containing decreased sugar levels and higher content of strawberry pulp were most preferred and presented the higher scores in the acceptance test. According the Principal Component Analysis, sample B3 was characterized by strawberry flavor and aroma, acid taste, strawberry seeds presence, sheep aroma, fatty flavor, and pinkish color; while sample B4 was associated with reddish color, astringent flavor, bitter taste, brightness, viscous, sweet, acid and rancid aromas attributes. Finally, sample B2 presented salt and sweet taste, and thinner texture, while samples B1 presented sheep flavor, cooked aroma, cooked flavor and residual flavor. Our findings suggest that formulation should contain 550/370/50 g/L of skimmed sheep milk, strawberry pulp and sugar in beverage. Highlights • Sensory evaluation of prebiotic strawberry pulp sheep milk beverage. • Decreased sugar level and higher strawberry pulp content improved the preference. • Decreased sugar level and higher strawberry pulp content improved the acceptance. [ABSTRACT FROM AUTHOR]

This paper seeks to explain the structural effect on selected properties of freeze-dried gels with different compositions and aeration times. Herein, sugars and citric acid were added to gels with low-methoxyl pectin, mixtures of xanthan gum and locust bean gum, as well as xanthan gum and guar gum, in order to obtain a strawberry model. Strawberry pulp was also added to hydrocolloids to develop an innovative strawberry product. All samples were aerated for 3 and 7 min, and freezedried. Composition changes were found to modify the structure of the examined samples and properties. Freeze-dried gels with low-methoxyl pectin seemed to reflect the best approach towards obtaining an innovative strawberry product with a tailored structure, as they had the best water absorbent capacity, and the most attractive and delicate structure. Samples with a mixture of hydrocolloids were more compact. Aeration time did not significantly affect the examined parameters, while the addition of sugar and citric acid increased them. The strawberry pulp experiment confirmed the strawberry model (with low-methoxyl pectin gels, and sugar and citric acid), which had the finest structure and the best rehydration properties. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The inactivation of bacteria naturally present in strawberry pulp was investigated after high hydrostatic pressure ( HHP) treatment at pressure levels up to 600 MPa at 25 °C for 5 ~ 25 min. Five strains of pressure-resistant bacteria designated as A, B, C, D and E were isolated and identified. The five strains were gram-positive, spore-forming, rods or rod in chains. Growth of the strains was observed at 30 ~ 45 °C, and strain B also grew well at 55 °C. They could produce acid from glucose and were catalase-positive. Analysis of 16S r RNA gene sequences showed that the five strains belonged to the genus Bacillus. Strain A and D exhibited the greatest 16S r RNA gene sequence similarity of 99% with B. licheniformis and B. firmus, respectively. By combination of phenotypic characteristics and 16 S rRNA gene sequences, strain C was B. mycoides and E was B. pumilus. On the basis of physiological and biochemical characteristics, gyr B gene sequences analysis and whole-cell fatty acids analysis, strain B was B. amyloliquefaciens. Further studies showed that strain B ( B. amyloliquefaciens) exhibited the highest pressure resistance, and it was reduced by 4.62-log after treatment at 600 MPa for 25 min at 25 °C as the most effective observed inactivation. [ABSTRACT FROM AUTHOR]

• HPU treatment affected the rheological properties of strawberry pulp. • HPU-treated strawberry WSP was studied. • High PME activity after HPU caused lower esterified pectin. • HPU treatment decreased the free Ca2+ content in the strawberry pulp. • HPU treatment might promote the interaction of low-methylated pectin and free Ca2+. This study investigated the effects of high-power ultrasound (HPU, 0–45 °C, 242–968 W/cm2, 2–16 min) on the rheological properties of strawberry pulp. Following the HPU treatment, the strawberry pulp exhibited an increase in apparent viscosity, storage modulus (G′), and loss modulus (G″). The water-soluble pectin (WSP), pectin methylesterase (PME) activity, and free calcium ions (Ca2+) of the strawberry pulp after HPU treatment were investigated to determine a possible reason for this phenomenon. HPU caused a significant decrease in the degree of esterification (DE), molecular weight (Mw), and particle size of strawberry WSP, but no significant changes were evident in the galacturonic acid (GalA) content and the zeta (ζ)-potential (P > 0.05), resulting in decrease in the apparent viscosity. Moreover, the largest reduction of PME activity was 22.6% after HPU treatment at 605 W/cm2 and 45 °C for 16 min, indicating that the PME was resistant to the HPU treatments. The free Ca2+ content in the strawberry pulp was significantly decreased after exposure to HPU (P < 0.05). The maximal reduction of 52.01% in the free Ca2+ was achieved at 605 W/cm2 and 45 °C for 16 min. The overall results indicated that the high residual activity (RA) of PME after HPU might induce the low esterification of WSP, while HPU promoted the interaction of free Ca2+ and low-methylated pectin, to form the network structure of Ca2+-low-methylated pectin, resulting in an increase in viscosity in the complex strawberry system. [ABSTRACT FROM AUTHOR]