Screening of volatile organic compounds emitted from different packaging materials: case study on fresh-cut artichokes

In the present work, the emission of volatile organic compounds (VOCs) from plastic packaging materials and their migration to the packaged product was investigated. Fresh-cut artichokes were chosen as a case study owing to their nutritional profile, including phenolic compounds, antioxidants, inulin and fiber, and the high market demand. Artichokes were cut into quarters, packaged in active modified atmosphere (5% O2 and 10% CO2) in three different micro-perforated (MP) packages (polypropylene (PP), polypropylene/polyamide (PP/PA) and polylactic acid (PLA)) and stored for 10 days at 5° C. For the detection of VOCs on the packaging materials and in the packaged product, three approaches were considered. First, VOCs emitted from a piece of package were extracted by solid phase micro extraction (SPME), at 30°C, and analyzed by gas-chromatography coupled to mass spectrometry (GC–MS). Second, VOCs from the headspace of the empty closed bag were extracted by SPME, at 5°C, to understand if any packaging volatile compound was transferred into the package atmosphere in this temperature condition. Finally, packaged artichokes were also analyzed by SPME/GC–MS to detect any presence of packaging volatiles compared to the fresh product. Emitted VOCs were different according to the material; in particular PP/PA emitted the greatest number of VOCs, most of them belonging to the class of branched alkanes and alkenes, such as 4-methyl-heptane, 2,4-dimethyl-heptane, 4-methyl-octane and 2,4 dimethyl heptene; PP emitted octane, aldehydes, and 1-metoxy-2-propanol; PLA emitted aldehydes and propanoic acid. Some VOCs were found into the atmosphere of the empty bags as well as on packaged artichokes, while they were not found in the fresh samples before packaging, suggesting that a study on the emission of VOCs from different plastic materials in contact with food and on the effect of different storage conditions is very critical for a better understanding of this issue

Perancangan Dan Pembuatan Sistem Pengaturan Pencahayaan Berbasis Mikrokontroler Atmega 16 Pada Budidaya Bunga Krisan (Chrysanthemum Sp) Di Dalam Greenhouse

Penelitian ini adalah bertujuan untuk membuat sistem pengaturan pencahayaan otomatis berbasis mikrokontroler Atmega 16 pada budidaya bunga krisan (chrysanthemum sp). Adapun proses dari penelitian ini adalah melakukan rancang bangun greenhouse berstandar SNI 7604:2010 untuk bunga krisan (Chrysanthemum sp), melakukan rancang dan bangun sistem pengaturan pencahayaan berbasis mikrokontroler pada budidaya bunga krisan Chrysanthemum sp, dan melakukan pengujian dengan menggunakan greenhouse berukuran luas selama 5 hari. Hasil penelitian menunjukkan bahwa, alat Pengontrol cahaya yang dibuat dengan kontrol yang diberikan yakni mikrokontroler Atmega 16 sebagai processor pengendali dan sensor-sensor berupa sensor photo dioda yang diberikan dapat berjalan dengan baik, pengujian sistem di dalam greenhouse dengan membandingkan intensitas cahaya di dalam greenhouse dan di luar greenhouse selama 5 hari untuk mengontrol pencahayaan yang dibutuhkan bunga krisan terbukti bahwa alat pengontrol pencahayaan dapat mengatur kondisi pencahayaan sesuai batas tumbuh optimal bunga krisan yaitu pada intensitas cahaya 20.000 Lux sampai dengan 42.000 Lux. Pada pengujian statistik paired t test harga t hitung adalah 2,94 dibanding dengan t tabel sehingga = 1,699, sehingga 2,94 > 1,699 (t hitung > t tabel), yang artinya ada beda secara signifikan antara intensitas cahaya di dalam greenhouse dengan intensitas cahaya lingkungan. Atau dengan kata lain pemberian mikrokontroler pengaturan pencahayaan di dalam greenhouse efektif untuk mengondisikan pencahayaan yang sesuai untuk bunga krisan

Quality of Goji Berry Fruit (<i>Lycium barbarum</i> L.) Stored at Different Temperatures

Goji berries are widely known for their outstanding nutritional and medicinal properties; they are usually found in the market as dried fruit or as juice because the fruit has a short shelf-life, and little information is available about its postharvest behavior at low temperatures. This study aimed to determine the storage performance of goji berry fruit by evaluating physicochemical, and sensorial attributes during storage at three different temperatures (0, 5, and 7 °C) for 12 days in a range that has not been extensively studied before. In addition, fruit respiration and ethylene production rates were also measured at the three temperatures. Fruit stored at 0 °C showed the lowest respiration rate and ethylene production (5.8 mg CO2 kg−1h−1 and 0.7 µg C2H4 kg−1h−1, respectively); however, at this temperature, the incidence and severity of pitting and electrolytic leakage were the highest. In contrast, 5 °C was found to be the best storage temperature for goji berry fruit; the fruit appeared fresh and healthy, had the highest scores during sensory analysis with an acceptable general impression, and had the lowest amount of damage attributable to chilling injury, with 17.1% fruit presenting with shriveling, 12.5% pitting, 6.7% mold, and 35% electrolytic leakage on day 9 of storage. Storage of goji berries at 7 °C resulted in the lowest marketability and the highest incidence of decay. Significant differences were also found in the phytochemical attributes, vitamin C content, soluble solid content (SSC), titratable acidity (TA), SSC/TA ratio, total polyphenol content, 2,2-diphenylpicrylhydrazy (DPPH), and anthocyanin content. This study revealed that a storage temperature of 5 °C for 9 days is recommended to maintain the quality of fresh goji berry. Thus, broadening the existing knowledge of the postharvest behavior of fresh goji berries; our results can help improve the commercial life of goji berries and ensure high-quality attributes throughout distribution

Identification of UV-fluorescence components associated with and detection of surface damage in green pepper (Capsicum annum L)

Fluorescence imaging has been used to detect fruit surface damage, but has not yet been applied to vegetables, such as green pepper. In this report, we extract and identify fluorescent components from the exocarp (skin) of green pepper. The fluorescence excitation and emission wavelengths of these extracted compounds were determined using a fluorescence spectrophotometer and identified using nuclear magnetic resonance spectroscopy and mass spectrometry. Red and blue fluorescent components with excitation and emission wavelengths 667 – 685 nm and 400 - 438 nm respectively, were found. In subsequent research, the red fluorescent compounds were targeted, as these compounds have a higher fluorescence intensity, around 97 a.u. Pheophytin a is one of these red fluorescent compounds, appearing in the mass spectrum at 871 m/z. Furthermore, when a fluorescence imaging system was set up, with halogen illumination, it was shown that this system could successfully detect surface damage in green pepper

Pomegranate Husk Scald Browning during Storage: A Review on Factors Involved, Their Modes of Action, and Its Association to Postharvest Treatments

The pomegranate (Punica granatum L.), which contains high levels of health-promoting compounds, has received much attention in recent decades. Fruit storage potential ranges from 3 to 4 months in air and from 4 to 6 months in Controlled Atmospheres (CA) with 3&ndash;5% oxygen and 10&ndash;15% carbon dioxide. Storage life is limited by decay, chilling injury, weight loss (WL), and husk scald. In particular, husk scald (HS) limits pomegranate long-term storage at favorable temperatures. HS appears as skin browning which expands from stem end towards the blossom end during handling or long-term storage (10&ndash;12 weeks) at 6&ndash;10 &deg;C. Even though HS symptoms are limited to external appearance, it may still significantly reduce pomegranate fruit marketability. A number of postharvest treatments have been proposed to prevent husk scald, including atmospheric modifications, intermittent warming, coatings, and exposure to 1-MCP. Long-term storage may induce phenolic compounds accumulation, affect organelles membranes, and activate browning enzymes such as polyphenol oxidases (PPO) and peroxidases (POD). Due to oxidation of tannins and phenolics, scalding becomes visible. There is no complete understanding of the etiology and biochemistry of HS. This review discusses the hypothesized mechanism of HS based on recent research, its association to postharvest treatments, and their possible targets

Is pomegranate husk scald during storage induced by water loss and mediated by ABA signaling?

Background: Husk scald (HS) is a physiological disorder limiting the marketability of pomegranate fruit during long-term storage. Herein we propose that HS is triggered by water loss and mediated by ABA signaling. Therefore, pomegranate fruit were stored at three different storage temperatures (3.5, 7 and 11°C) and 96.5%&nbsp;± 2.3% relative humidity (RH) evaluating weight loss (WL), abscisic acid (ABA), respiration rate (RR), total phenolics (TP), total anthocyanin (TA), antioxidant activity (AA), exocarp electrolyte leakage (EL), malondialdehyde (MDA), color attributes, browning index and visual quality of fruit. Results: HS appeared after 3 months of storage at 11 °C, less at 7°C and non-present at 3.5°C. Incidence of HS occurred along with higher WL, RR, EL, MDA, and ABA content. Conversely, TP, TA and AA decreased significantly. WL increased with water vapor pressure deficit (VPD) at higher temperatures. After 93 days, 11 °C fruit reached ~10% WL while ABA increased to ~150&nbsp;μg kg-1 . However, 3.5 and 7&nbsp;°C fruit, reached 5 and 7% WL while ABA was ~31 and 75&nbsp;μg kg-1 , respectively. Conclusion: Herein, we propose a mechanistic model of HS development where water stress induces ABA as a primary signaling molecule that triggers the HS response mediated by reactive oxygen species (ROS). Accumulation of ROS induces phenolic biosynthesis and oxidative stress promotes loss of membrane compartmentalization that induces phenolic degradation. Ultimately, husk scalding becomes visible due to the oxidation of phenolics into brown pigments. © 2022 Society of Chemical Industry

Early discrimination of mature-and immature-green tomatoes (Solanum lycopersicum L.) using fluorescence imaging method

Detecting mature-green and immature-green tomatoes using non-destructive approaches is a challenge for the fresh produce industry. Hyperspectral fluorescence imaging technique with excitation wavelength at 365 nm and UV–vis CCD camera was used for early non-destructive detection of mature-green and immature-green fruit from 200 randomly harvested green tomatoes. Conventional destructive analysis regarding locule gel development and seed texture were assessed to assign the maturity stage of the fruit. In addition soluble solid content (SSC), pH, total acidity (TA), and color were measured, on the training set and on the prediction set, in this case also after 10 d of storage. Fluorescence intensity at the surface of immature-green fruit was higher in the red region (690 nm) than that of mature-green fruit, suggesting that hyperspectral fluorescence imaging can be an effective classification tool. A univariate classification method was used to distinguish mature-green and immature-green tomatoes based on the grey scale values extracted from fluorescence imaging, with a non-error rate of 96 % in calibration and 100 % in external prediction. Hence, a non-destructive method for the early distinction of mature-green from immature-green tomatoes is available

Inclusion of Antifungal and Probiotic <i>Lactiplantibacillus plantarum</i> Strains in Edible Alginate Coating as a Promising Strategy to Produce Probiotic Table Grapes and Exploit Biocontrol Activity

The use of lactic acid bacteria (LAB) for the probiotic enrichment of minimally processed fruit is a well-established practice in the literature. In addition, several LAB demonstrated a strain-specific ability to control harmful microorganisms and decay agents, improving shelf life, maintaining quality, and promoting the safety of fruits and vegetables. Edible coatings can help modulate the phenomena of gas exchange and water loss by fruits, representing protection from physical damage and spoilage phenomena linked to oxidation and the development of undesired microorganisms. At the same time, the coating can represent an innovative delivery matrix for the LAB strains of potential interest to improve safety and quality in the postharvest management of fruits. In this work, five Lactiplantibacillus plantarum strains, previously characterised for their probiotic and antifungal activity, were incorporated into a sodium alginate coating to develop edible probiotic coatings with antifungal properties for table grapes cv. Italia. The bacterial transfer and their survival were evaluated by comparing coated and uncoated table grapes during 14 days of cold storage at 4 °C. The alginate edible coating increased the number of viable cells transferred to the surface of the berries from about 5 to more than 7 Log CFU/g, with a crucial impact on the potential functional attributes of the final product. The ability of the functionalised coatings to counteract the decay development was evaluated on table grape berries artificially contaminated with Aspergillus niger CECT 2805. A significant reduction in lesion diameter was observed in the alginate coating with L. plantarum 11-A, with a reduction from 15.40 ± 1.14 mm of uncoated berries to 8.40 ± 1.14 mm of berries coated with L. plantarum 11-A. The lesion diameter reduction was also accompanied by a reduction in the symptoms of infection, such as browning around the wound. These results suggest the application of selected strains of L. plantarum as promising bio-resources to enhance the overall value of ready-to-eat fruits and vegetables, particularly in combination with edible coating as a carrier matrix. While a strain-dependent effect was not detected with respect to the improvement in the number of cells in the edible coating, a variability depending on the biotype used was detected for the properties linked to biocontrol, suggesting that the inclusion in edible packaging may represent an innovative criterion in the selection of lactobacilli to be applied postharvest

Potential application of hyperspectral imaging and FT-NIR spectroscopy for discrimination of soilless tomato according to growing techniques, water use efficiency and fertilizer productivity

Background: This study aimed to test the potential of nondestructive optical techniques for classifying sustainable-produced tomatoes according to a) growing practices; b) levels of water use (WUE) and partial factor productivity of nutrients (PFP). Three distinct hydroponic growing techniques for water and fertilizer use were applied over two cultivation cycles for two varieties (cv 'Carminio', and cv 'Mose'): i) free drain open cycle cultivation (OPEN); ii) open cycle cultivation with on-demand sensor-based fertigation (SMART); iii) closed cycle cultivation (CLOSED). Hyperspectral images (HSI) in the Vis-NIR and NIR range, as well as reflectance spectra obtained through Fourier Transform (FT)-NIR spectroscopy, were acquired throughout the harvesting period, with approximately 300 fully ripe tomatoes obtained per variety. For each variety, partial least squares discriminant analysis (PLS-DA) was initially employed to discriminate the three cultivation systems and subsequently distinguish two levels of WUE and PFP, per variety. Finally, the data obtained from both varieties were combined and PLS-DA utilized to categorize three levels of WUE: LOW, MEDIUM, and HIGH. Results: The PLS-DA models applied in external prediction for discriminating tomatoes of each variety according the three cultural practices achieved accuracy higher than 79.55 % for data obtained with FT-NIR and HSI in the Vis-NIR range, and lower for HSI (NIR). The performance increased when considering only two distinct classes (based on WUE and nutrients PFP) with accuracy, specificity, and sensitivity higher than 86 %. General models based on spectra obtained with HSI Vis-NIR, using data over the two varieties to classify tomato according to three levels of WUE, yielded accuracy and specificity of 89.8 % and 91.7 %, respectively, utilizing only 20 variables. Conclusions: Results of this study indicated the effectiveness of FT-NIR and HSI (Vis-NIR) techniques for discrimination of tomato fruits cultivated with varying levels of water and fertilizers. Further validation of these methods is needed before their widespread application to support the adoption of low input growing techniques