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This study introduces an effective solution to enhance the postharvest preservation of broccoli, a vegetable highly sensitive to ethylene, a hormone produced by climacteric fruits such as tomatoes. The proposed method involves a triple combination of ethylene elimination techniques: potassium permanganate (KMnO4) filters combined with ultraviolet radiation (UV-C) and titanium oxide (TiO2), along with a continuous airflow to facilitate contact between ethylene and these oxidizing agents. The effectiveness of this approach was evaluated using various analytical techniques, including measurements of weight, soluble solids content, total acidity, maturity index, color, chlorophyll, total phenolic compounds, and sensory analysis conducted by experts. The results demonstrated a significant improvement in the physicochemical quality of postharvest broccoli when treated with the complete system. Notably, broccoli subjected to this innovative method exhibited enhanced organoleptic quality, with heightened flavors and aromas associated with fresh green produce. The implementation of this novel technique holds great potential for the food industry as it reduces postharvest losses, extends the shelf life of broccoli, and ultimately enhances product quality while minimizing waste. The successful development and implementation of this new technique can significantly improve the sustainability of the food industry while ensuring the provision of high-quality food to consumers.

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Nuts are widely consumed worldwide, mainly due to their characteristic flavor and texture, ease of consumption, and their functional properties. In addition, consumers increasingly demand natural or slightly processed foods with high quality. Consequently, non-thermal treatments are a viable alternative to thermal treatments used to guarantee safety and long shelf life, which produce undesirable changes that affect the sensory quality of nuts. Non-thermal treatments can achieve results similar to those of the traditional (thermal) ones in terms of food safety, while ensuring minimal loss of bioactive compounds and sensory properties, thus obtaining a product as similar as possible to the fresh one. This article focuses on a review of the main non-thermal treatments currently available for nuts (cold plasma, high pressure, irradiation, pulsed electric field, pulsed light, ultrasound and ultraviolet light) in relation to their effects on the quality and safety of nuts. All the treatments studied have shown promise with regard to the inhibition of the main microorganisms affecting nuts (e.g., Aspergillus, Salmonella, and E. coli). Furthermore, by optimizing the treatment, it is possible to maintain the organoleptic and functional properties of these products.

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Shelled walnuts are considered a microbiologically low-risk food but have been linked to some outbreaks, and a treatment aiming to decrease this risk is desirable. Pulsed light (PL) may be an alternative, providing it does not seriously impair their quality. This work assessed the impact of PL on some quality attributes of walnuts. To do this, measurements of rancidity, volatiles, total phenols, antioxidant activity, and descriptive sensory analysis were carried out on untreated and PL (43 J/cm2)-treated kernels. PL had no statistically significant (p > 0.05) effects on TBARS, peroxide value, total phenols, and antioxidant activity but significantly increased the concentration of volatiles related to green/herbaceous odors and decreased compounds related to fruity and citrus odors. The descriptors nut overall, walnut odor and flavor, and aftertaste were given statistically significantly (p < 0.05) higher scores, while descriptors woody odor and sweet received lower scores; 16 other traits such as all those related to color, texture, and rancidity were unaffected. No significant (p > 0.05) effects on total phenols and antioxidant activity in general were observed during the course of PL treatment. It can be concluded that PL technology may be used in shelled walnuts with only mild effects on their quality; a storage study must be carried out in order to determine the effect of PL treatment on its shelf-life.

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Brettanomyces bruxellensis is a wine spoilage yeast that could be inactivated by pulsed light (PL); however, this technology may induce changes in the quality of this alcoholic drink. The present research aimed to determine the potential of PL to inactivate B. bruxellensis inoculated in white wine and to assess the effect of this technology on the color and aromatic profile of the wine. For this, a cocktail of B. bruxellensis strains was inoculated into the wine and its inactivation by PL was determined and fitted to a microbial inactivation model. Along with this, the effect of PL on instrument-measured color, and the volatile compounds of the wine were evaluated by GC/MS and descriptive sensory analysis, respectively. B. bruxellensis was inactivated according to the Geeraerd model including the tail effect, with a maximum inactivation of 2.10 log reduction at 10.7 J/cm2; this fluence was selected for further studies. PL affected wine color but the total color difference was below the just noticeable difference at 10.7 J/cm2. The concentration of 13 out of 15 volatile compounds decreased due to the PL, which was noticeable by the panel. It is not clear if these compounds were photolyzed or volatilized in the open reactor during treatment. In conclusion, PL is able to inactivate B. bruxellensis in white wine but the treatment impairs the volatile profile. The use of a closed reactor under turbulent flow is recommended for disaggregating yeast clumps that may cause the tailing of the inactivation curve, and to avoid the possible escape of volatile compounds during treatment.

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The Schlieren method has been used before to visualize weak shock waves radiated from the open ends of brass instruments, but no attempt has previously been undertaken, however, to measure the geometry of the radiated wavefronts using the Schlieren images. In this paper Schlieren visualization is used to estimate the geometry of the two-dimensional shock wavefronts radiated from the bell of a trumpet at different frequencies. It is observed that the geometry of the shocks does change with frequency, in the expected manner. The propagation speeds of these shocks are also calculated, and they too exhibit the anticipated behavior.

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Current techniques for measuring normal incidence sound transmission loss with a modified impedance tube, or transmission tube, require setting up two different absorbing termination loads at the end of the downstream tube [ASTM E2611-09, Standard Test Method for Measurement of Normal Incidence Sound Transmission of Acoustical Materials Based on the Transfer Matrix Method (American Society for Testing and Materials, West Conshohocken, 2009)]. The process of physically handling the two required passive absorbing loads is a possible source of measurement errors, which are mainly due to changes in sample test position, or in test setup re-assembly, between measurements. In this paper, a modified transmission tube apparatus is proposed for non-intrusively changing the downstream acoustic load by means of a combined passive-active termination. It provides a controlled variable sound absorption which simplifies the setup of standard two-load techniques, without the need of physically handling the apparatus during the tests. This virtually eliminates the risk of errors associated with the physical manipulation of the two passive terminations. Transmission loss measurements in some representative test conditions are reported, showing improvements over current implementations, in reducing by approximately 50% the measurement variations associated with the setup of the two required absorbing terminations. Measurement results agree within 0.4 dB (maximum difference in high resolution broadband), and 0.04 dB (mean difference in 1/3-octave bands), with those obtained using standard passive two-load methods.

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UNLABELLED: The effects of the addition of cyclodextrins (CDs), ß-CD, or HP-ß-CD (1%), on the protection of antioxidant compounds of mandarin juices enriched with pomegranate extract and goji berries juice, was studied. Juices were prepared and after their thermal treatment (98 °C, 30 s) they were stored at 4 °C during 75 d. Vitamin C content, CIE L*a*b* color, antioxidant capacity, retinol equivalents, and sensory properties were studied. Losses on vitamin C were higher (6%) for juices with ß-CD than juices with HP-ß-CD. Retinol equivalents degradation was lower (3.4%) in juices with HP-ß-cyclodextrins than in those treated with ß-CD. Lower losses were observed for the instrumental and sensory color intensity in juices with HP-ß-CD addition. Finally, the antioxidant capacity was also higher in juices treated with HP-ß-CD. Finally, the overall sensory quality of juices with HP-ß-CD was the best one after 30 d of cold storage. Even though ß-CD addition did not cause any improvement compared with control juice (without CD addition), the benefits of adding HP-ß-CD to this particular juice were shown in almost all parameters under study. PRACTICAL APPLICATION: The present study deals with the practical aspects of the utilization of CDs and CD-complexes in the food industry. The molecular encapsulation of lipophilic food ingredients with CD are supposed to improve the stability of flavors, vitamins, colorants, and antioxidant activity, leading to extended product shelf life. The HP-ß-CD treated mandarin juice enriched with pomegranate extract and juice of goji berries will have a more intense color, higher vitamin C content, retinol equivalents, and antioxidant activity during storage and shelf life than control juices, with no CD addition.

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The propagation of finite-amplitude waves inside a slide trombone is studied through direct pressure measurements corresponding to dynamic extremes. A two-microphone method is used to separate left-moving and right-moving waves inside the trombone, permitting the detection of nonlinear effects associated with progressive waves. It is found that a redistribution of energy across the spectrum toward the higher-frequencies occurs for large distances and high initial pressure levels. These results are consistent with the theory of weakly nonlinear acoustics and also with those reported in this same context by other authors, but which have been obtained mostly through examination of standing-waves.

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In recent years, the use of cyclodextrins (CDs) as antibrowning agents in fruit juices has received growning attention. However, there has been no detailed study of the behavior of these molecules as substances, which can lead to the darkening of foods. In this paper, when the color of fresh banana juice was evaluated in the presence of different CDs, the evolution of several color parameters was the opposite of that observed in other fruit juices. Moreover, a kinetic model based on the complexation by CDs of the natural browning inhibitors present in banana is developed for the first time to clarify the enzymatic browning activation of banana juice. Finally, the apparent complexation constant between the natural polyphenoloxidase inhibitors present in banana juice and maltosyl-beta-CD was calculated (Kci = 27.026 +/- 0.212 mM (-1)).

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Consumers demand organic products because they believe they are more flavorful and respectful to the environment and human health. The effects of conventional, integrated, and organic farming, grown in a controlled greenhouse, on color, minerals, and carotenoids of sweet pepper fruits ( Capsicum annuum), cv. Almuden, were studied. Experimental results proved that organic farming provided peppers with the highest (a) intensities of red and yellow colors, (b) contents of minerals, and (c) total carotenoids. Integrated fruits presented intermediate values of the quality parameters under study, and conventional fruits were those with the lowest values of minerals, carotenoids, and color intensity. As an example, the concentrations of total carotenoids were 3231, 2493, and 1829 mg kg (-1) for organic, integrated, and conventional sweet peppers, respectively. Finally, organic red peppers could be considered as those having the highest antioxidant activity of all studied peppers (agricultural farming and development stage).

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UNLABELLED: Although cyclodextrins (CDs) have been successfully used as antibrowning agents in different fruit juices, no research has studied the effect of these compounds on enzymatic browning in peach juice. In this paper, the color of fresh peach juice was evaluated in the presence of two types of natural (alpha-CD and beta-CD) and a modified (maltosyl-beta-CD) CD, and the effectiveness of these compounds as browning inhibitors was determined using the color space CIELAB system. Moreover, to clarify the mechanism by which CDs inhibit peach juice enzymatic browning, the process was kinetically modeled in the absence and presence of CDs using a colorimetric method; the apparent complexation constants between the mixtures of diphenols present in peach juice and some types of CD were calculated. The results show that the highest affinity constant was presented by alpha-CD (Kc = 18.31 mM-1) followed by maltosyl-beta-CD (Kc = 11.17 mM-1), whereas beta-CD was incapable of inhibiting peach juice enzymatic browning. KEYWORDS: Cyclodextrin; browning; peach; juice; color; polyphenol oxidase.

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The complexation of trans-resveratrol with beta-cyclodextrin (beta-CD) was investigated using reversed-phase liquid chromatography and mobile phases to which beta-CD was added. The decrease in the retention times with increasing concentrations of beta-CD (0-2.5 mM) showed that trans-resveratrol forms a 1:1 complex with beta-CD, while the apparent formation constants (K(F)) were strongly dependent of the water-methanol proportion of the mobile phase employed. A slight decrease in K(F) was observed at 50-55% water in the mobile phase but a large increase from 55 to 70% water. The values of K(F) for the trans-resveratrol-beta-CD interaction decreased when the temperature was raised from 20 to 37 degrees C. In order to gain information about the mechanism aspect of the trans-resveratrol affinity for beta-CD, the thermodynamic parameters of the complexation were obtained. Complex formation of trans-resveratrol with beta-CD (DeltaG degrees =-17.01 kJ/mol) is largely driven by enthalpy (DeltaH degrees = -30.62 kJ/mol) and slightly entropy changes (DeltaS degrees = -45.68 J/mol K).

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Dominga grape polyphenol oxidase (PPO) was extracted using phase partitioning with Triton X-114. The enzyme was obtained in latent state and could be optimally activated by the presence of 0.2% sodium dodecyl sulfate (SDS) at pH 6.0. In the absence of SDS, the enzyme showed maximum activity at acid pH. The kinetic parameters of the enzyme at pH 3.0 and 6.0 in the presence of SDS were calculated. The effect of several inhibitors was studied, tropolone being the most effective with a K(i) value of 18 muM. The effect of cyclodextrins was also studied, and the complexation constant K(c) between G(2)-beta-cyclodextrins and 4-tert-butylcatechol was calculated using the enzymatic method (K(c) = 13960 M(-)(1)). The evolution of the color parameters (L, a, b) of liquefied grape berries was inhibited by inhibitors of PPO activity, such as diethyldithiocarbamate, metabisulfite, and G(2)-beta-cyclodextrins, indicating that enzymatic browning by PPO is the main process involved in the browning of Dominga grape juice at room temperature.

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