Effect Of Ultrasound Processing Research Articles

The effect of ultrasound process on lactic acid bacteria, physicochemical and sensory properties of yoghurt, before and after inoculation of starter cultures into milk

The effect of ultrasound (US) applied before (US + i) and after (i + US) inoculation of yoghurt starter into cows' milk on some parameters of yoghurt was investigated. Lightness (L*) values, amounts of acetaldehyde, diacetyl, acetoin, ethanol, lactic, pyruvic, and acetic acid were higher in the US‐treated groups compared with control (P < 0.05). In the US + i group, the total amount of ketones increased. Lactobacillus and Streptococcus spp. numbers reached log ≥7.0 cfu/g in all groups (P > 0.05). It can be concluded that low‐intensity ultrasound applied to cows' milk before or after inoculation of yoghurt starters increases the aroma components and organic acid content of yoghurt.

Effect of ultrasound processing on rheological properties and color of green food products.

Changes in rheological behavior and physical properties of avocado dressing and green juice samples processed by ultrasound (US) technology (120 µm, 24 kHz, up to 2 min, 20 °C) were investigated. The avocado dressing followed pseudoplastic flow behavior, which had good fit to the power law model, with R2 values >0.9664. The lowest K values 3.5110, 2.4426, and 2.3228 were determined for avocado dressing samples with no treatment at 5 °C, 15 °C, and 25 °C, respectively. At the shear rate of 0.1/s, viscosity of 2 min US-treated avocado dressing increased significantly from 19.1 to 55.5 Pa.s at 5 °C, 13.08 to 36.78 Pa.s at 15 °C, and 14.55 to 26.75 Pa.s at 25 °C. Flow instability occurred in green juice after reaching shear rate of 300/s due to narrow gap in concentric cylinder; however, constant viscosity between 10 and 300/s indicated that the sample was Newtonian. Increasing temperature from 5 °C to 25 °C decreased viscosity of US-treated green juice from 2.55 to 1.50 mPa.s at the shear rate of 100/s. Color of both samples did not change after US processing, but lightness increased in green juice which denoted lighter color compared to the sample without treatment. There was no difference in pH and total soluble solids of samples. Results represent that US technology may be a good alternative in producing green liquid foods with acceptable rheological properties and color.

Impact of ultrasound processing on alternative protein systems: Protein extraction, nutritional effects and associated challenges.

Proteins from alternative sources including terrestrial and aquatic plants, microbes and insects are being increasingly explored to combat the dietary, environmental and ethical challenges linked primarily to conventional sources of protein, mainly meat and dairy proteins. Ultrasound (US) technologies have emerged as a clean, green and efficient methods for the extraction of proteins from alternative sources compared to conventional methods. However, the application of US can also lead to modifications of the proteins extracted from alternative sources, including changes in their nutritional quality (protein content, amino acid composition, protein digestibility, anti-nutritional factors) and allergenicity, as well as damage of the compounds associated with an increased degradation resulting from extreme US processing conditions. This work aims to summarise the main advances in US equipment currently available to date, including the main US parameters and their effects on the extraction of protein from alternative sources, as well as the studies available on the effects of US processing on the nutritional value, allergenicity and degradation damage of these alternative protein ingredients. The main research gaps identified in this work and future challenges associated to the widespread application of US and their scale-up to industry operations are also covered in detail.

Food-Package-Processing relationships in emerging technologies: Ultrasound effects on polyamide multilayer packaging in contact with different food simulants

In this study, the effect of ultrasound processing on the properties of two packages widely used in food products was evaluated: polyamide (PA) and polyethylene (PE) multilayer packaging. Packages composed of PE/PA/PE (Film A) and PE/PA/PE/PA/PE (Film B) were filled with aqueous and fatty food simulants and treated in an ultrasound water bath (frequency 25 kHz, volumetric power of 9.74 W/L, temperature of 25 °C, and time of 30 and 60 min). Materials were evaluated in term of structure and performance properties. Ultrasound did not or induced small changes in chemical groups, crystallinity, melting temperature, and tensile strength of the films. Film A showed a reduction in heat sealing tensile strength of 25% in the machine direction and 22% in the transverse direction. Film B showed a 20% increase of water vapor transmission rate after ultrasound processing. Although ultrasound had little impact on the properties of the evaluated materials, these modifications do not compromise the use of these packages for applications in ultrasound-processed foods. Therefore, the results indicate that ultrasound can be used as a food processing technology in multilayer PA and PE packaging.

Understanding the effects of ultrasound processng on texture and rheological properties of food.

The demand for the production of high quality and safe food products has been ever increasing. Consequently, the industry is looking for novel technologies in food processing operations that are cost-effective, rapid and have a better efficiency over traditional methods. Ultrasound is well-known technology to enhance the rate of heat and mass transfer providing a high end-product quality, at just a fraction of time and energy normally required for conventional methods. The irradiation of foods with ultrasound creates acoustic cavitation that has been used to cause desirable changes in the treated products. The technology is being successfully used in various unit operations such as sterilization, pasteurization, extraction, drying, emulsification, degassing, enhancing oxidation, thawing, freezing and crystallization, brining, pickling, foaming and rehydration, and so forth. However, the high pressure and temperature associated with the cavitation process is expected to induce some changes in the textural and rheological properties of foods which form an important aspect of product quality in terms of consumer acceptability. The present review is aimed to focus on the effects of ultrasound processing on the textural and rheological properties of food products and how these properties are influenced by the process variables.

Effects of Ultrasound Processing on Physicochemical Parameters, Antioxidants, and Color Quality of Bayberry Juice

Effects of ultrasound on physicochemical parameters, ascorbic acid, anthocyanins, polymeric color (PC), 5-hydroxymethylfurfural (HMF), browning degree (BD), color, and superoxide dismutase (SOD) activity of bayberry juice were investigated. Treatments were carried out at amplitude levels from 20 to 100% of total input power (600 W) at 20 kHz for 2–10 min. The results showed that no notable differences in pH, total soluble solids, titratable acidity, and yellowness b∗ values were found in ultrasound-treated samples. The HMF, PC, BD, and L∗ values of bayberry juice obviously increased with enhancing ultrasonic intensity and treatment time. The ascorbic acid exhibited no notable changes after ultrasound treatment at lower intensity levels for short time, while anthocyanins showed an increasing tendency. With increasing ultrasonic intensity and time, antioxidants gradually decreased. Furthermore, the SOD activity apparently increased at short-time treatment and then decreased with ultrasound processing extension.

Effect of ultrasound processing on the bioaccessibility of phenolic compounds and antioxidant capacity of selected vegetables.

Ultrasound processing can result in cell wall disruption, facilitating the release of the cellular content. Therefore, we hypothesized that sonication of vegetables could be used as a pre-treatment to increase the bioaccessibility of phenolic and antioxidant compounds. Overall, sonication (40kHz, 250W, 4°C, 20min) did not affect the main physicochemical parameters of tomato, lettuce, zucchini, and green and red pepper (p < 0.05). The polyphenolic content and antioxidant activity of digestive enzymatic extracts was higher than that of water:methanol extracts (p < 0.05). In addition, sonication resulted in increased bioaccessibility of phenolic compounds in lettuce and green pepper (p < 0.05), while no effect was observed for tomato, red pepper, and zucchini samples suggesting a matrix-dependent effect. The amount of phenolic compounds and antioxidants released by vegetables during a simulated gastrointestinal digestion may be higher than the one that can be expected from measurements in usual aqueous-organic extracts.

Ultrasound assisted enzymatic hydrolysis of sucrose catalyzed by invertase: Investigation on substrate, enzyme and kinetics parameters

This work studied the ultrasound technology as an alternative to enhance the reaction of sucrose inversion. To achieve it, the effect of ultrasound processing was evaluated in three situations: the reaction (invertase acting on substrate under ultrasound processing), the isolated substrate (sucrose) and the isolated enzyme (invertase). Ultrasound (25 kHz, 22 W/L) processing was conducted under different conditions of pH and temperature. The ultrasound assisted reaction was accelerated in relation to the conventional processing. This process increased the sucrose hydrolysis rate up to 33% at 40 °C, and 30% at 30 °C. The ultrasound as a pre-treatment method did not promote sucrose hydrolysis, but slightly reduced the invertase activity, independently of the pH and temperature of evaluation. Sonication also increased Vmax (increased of 23%) and maintained constant Km, indicating that the ultrasound accelerated mass transfer during the reaction, but did not directly affected the enzyme. In addition, the invertase catalytic efficiency enhanced 27% under sonication. Therefore, ultrasound technology emerges as an interesting alternative to improve the invertase performance, accelerating enzymatic reaction.

The Effect of Ultrasound Processing and Exogenous Cellulase Supplementation on the Ruminal Degradability of Palm Date Seeds

The objective of this study was to evaluate the effects of sonication and enzyme supplements on rumen degradability of date palm seeds (DPS). The effect of alkali-assisted sonication and the addition of cellulase enzyme supplements (40 endoglucanase units/g dry matter) derived from Aspergillus niger or Trichoderma longibrachiatum on DPS ruminal degradability were evaluated under in vitro conditions. The in vitro ruminal degradability of neutral detergent fiber (NDF) and organic matter (OM) for the unsonicated seeds was not affected (p>0.10) by enzyme supplements. On the other hand, alkali-assisted sonication increased the in vitro rumen degradability of seeds’ NDF and OM and the addition of Trichoderma longibrachiatum cellulase enzyme to sonicated seeds slightly but significantly increased (p<0.01) their in vitro NDF and OM degradability. The results indicate that sonication along with alkali pretreatment could improve the NDF and OM degradability of DPS in rumen. The pretreatment combined effect of ultrasound and Trichoderma longibrachiatum cellulase enzyme could be beneficial in increasing the inclusion rate of DPS in ruminant animals’ diets.

Effects of Ultrasound Processing on the Thermal and Retrogradation Properties of Nonwaxy Rice Starch

AbstractIn the present research, nonwaxy rice starch suspension (5%, dry basis) was processed by ultrasound. The relationship between temperature and ultrasonication time of rice starch suspension was investigated, and the effects of ultrasound power and time, intensity on the thermal and retrogradation properties of rice starch were evaluated. Thermal and retrogradation properties of rice starch were determined by a differential scanning calorimetry. The results of temperature values showed that temperature increased with ultrasonication time and power and ultrasound intensity; the higher the ultrasound power and intensity, the higher the temperature of rice suspension. The ultrasound thermal effects cause temperature increase and partly starch gelation during ultrasound processing. High ultrasound power and strong intensity can effectively change the onset temperature and enthalpy of rice starch, and change the retrogradation properties of rice starch; however, the low ultrasound power and intensity have less effects on the granule and properties of rice starch.Practical ApplicationsUltrasound technology is widely used in starch processing. This article shows the effects of ultrasound time, power and intensity on the thermal and retrogradation properties of nonwaxy rice starch suspensions. Ultrasound processing can significantly change the properties of nonwaxy rice starch, and the ultrasound thermal effects cause the temperature increase and partly starch gelation in nonwaxy rice starch suspension during ultrasound processing. The method of high ultrasound power with strong intensity is potentially very useful to produce high‐quality modification starch for the starch industry if the thermal effects of ultrasound are avoided.

Effect of ultrasound processing on anthocyanins and color of red grape juice

Grape juice samples were sonicated with processing variables of amplitude level (24.4–61.0 μm) and treatment time (0–10 min) at a constant frequency of 20 kHz and pulse durations of 5 s on and 5 s off. A full factorial experimental design with regression modeling was employed to investigate the main effects of amplitude level and treatment time on anthocyanins and color parameters. Significant effects of sonication on major anthocyanins cyanidin-3-O-glucosides (CA), malvanidin-3-O-glucosides (MA) and delphinidin-3-O-glucosides (DA), color values ( L*, a*, b*) and color index (CI) were observed. Prediction models were found to be significant ( p < 0.05) with low standard errors and high coefficients of determination ( R 2). Model predictions for critical quality parameters of anthocyanins (CA; MA; DA), color values ( L*, a*, b*), TCD and CI inactivation were closely correlated to the experimental results obtained. Significant retention of anthocyanin content in grape juice was observed for CA (97.5 %); MA (48.2 %) and DA (80.9%) during sonication. CI and other color combinations ( L* a* b*, L* a* /b* and L* b* /a*) were found to be strongly correlated with anthocyanin content. This study shows that sonication could be employed for as a preservation technique for fruit juice processing where anthocyanin retention is desired.

Effect of ultrasound processing on the quality and nutritional properties of fruit juices

Effect of ultrasound processing on the quality and nutritional properties of fruit juices