Rapid Estimation of Lycopene Concentration in Watermelon and Tomato Samples by Fiber Optic Visible Spectroscopy

Rapid lycopene sensing techniques using fiber optics and visible spectroscopy of watermelon flesh, watermelon puree and tomato puree were explored. Visible spectra of samples were correlated with lycopene concentrations determined by hexane extraction and spectrophotometry. Fiber optic probes consisting of a light emitting fiber and a detecting fiber connected to a miniature spectrometer were used for acquisition of visible spectra. An Absorbance Index (AI) and a Normalized Absorbance Index (NAI), obtained from the absorbance values at 700 nm and 565 nm were correlated with lycopene concentration. Partial Least Squares (PLS) regression models were developed from the absorbance values in the spectral range 500-750 nm. For watermelon flesh, spectra in transmittance and reflectance mode were correlated separately with lycopene concentration. For pureed samples of watermelon and tomato, only reflectance spectra were used. To study the effect of distance between light emitting and receiving fiber optics on reflectBiosystems and Agricultural Engineerin

Visible-NIR ‘point’ spectroscopy in postharvest fruit and vegetable assessment: The science behind three decades of commercial use

The application of visible (Vis; 400–750 nm) and near infrared red (NIR; 750–2500 nm) region spectroscopy to assess fruit and vegetables is reviewed in context of ‘point’ spectroscopy, as opposed to multi- or hyperspectral imaging. Vis spectroscopy targets colour assessment and pigment analysis, while NIR spectroscopy has been applied to assessment of macro constituents (principally water) in fresh produce in commercial practice, and a wide range of attributes in the scientific literature. This review focusses to key issues relevant to the widespread implementation of Vis-NIR technology in the fruit sector. A background to the concepts and technology involved in the use of Vis-NIR spectroscopy is provided and instrumentation for in-field and in-line applications, which has been available for two and three decades, respectively, is described. A review of scientific effort is made for the period 2015 - February 2020, in terms of the application areas, instrumentation, chemometric methods and validation procedures, and this work is critiqued through comparison to techniques in commercial use, with focus to wavelength region, optical geometry, experimental design, and validation procedures. Recommendations for future research activity in this area are made, e.g., application development with consideration of the distribution of the attribute of interest in the product and the matching of optically sampled and reference method sampled volume; instrumentation comparisons with consideration of repeatability, optimum optical geometry and wavelength range). Recommendations are also made for reporting requirements, viz. description of the application, the reference method, the composition of calibration and test populations, chemometric reporting and benchmarking to a known instrument/method, with the aim of maximising useful conclusions from the extensive work being done around the world

Sensors for product characterization and quality of specialty crops—A review

This review covers developments in non-invasive techniques for quality analysis and inspection of specialty crops, mainly fresh fruits and vegetables, over the past decade up to the year 2010. Presented and discussed in this review are advanced sensing technologies including computer vision, spectroscopy, X-rays, magnetic resonance, mechanical contact, chemical sensing, wireless sensor networks and radiofrequency identification sensors. The current status of different sensing systems is described in the context of commercial application. The review also discusses future research needs and potentials of these sensing technologies. Emphases are placed on those technologies that have been proven effective or have shown great potential for agro-food applications. Despite significant progress in the development of non-invasive techniques for quality assessment of fruits and vegetables, the pace for adoption of these technologies by the specialty crop industry has been slow

Design a CPW antenna on rubber substrate for multiband applications

This paper presents a compact CPW monopole antenna on rubber substrate for multiband applications. The multi band applications (2.45 and 3.65 GHz) is achieved on this antenna design with better antenna performances. Specially this antenna focused on ISM band application meanwhile some of slots (S1, S2, S3) have been used and attained another frequency band at 3.65 GHz for WiMAX application. The achievement of the antenna outcomes from this design that the bandwidth of 520 MHz for first band, the second band was 76 MHz for WiMAX application and the radiation efficiency attained around 90%. Moreover, the realized gain was at 4.27 dBi which overcome the most of existing design on that field. CST microwave studio has been used for antenna simulation

SPECTROSCOPY, IMAGE ANALYSIS AND HYPERSPECTRAL IMAGING FOR FOOD SAFETY AND QUALITY: A CHEMOMETRIC APPROACH

Questo progetto di dottorato studia le differenti applicazioni delle tecniche ottiche non distruttive per la valutazione della qualit\ue0 e della shelf-life di prodotti vegetali cos\uec come l\u2019identificazione precoce di sviluppi microbici su superfici industriali. La spettroscopia, l\u2019analisi dell\u2019immagine e l\u2019analisi dell\u2019immagine iperspettrale possono giocare un ruolo importante nella valutazione sia della qualit\ue0 che della sicurezza degli alimenti grazie alla rapidit\ue0 e sensibilit\ue0 della tecnica, specialmente quando si utilizzano strumenti semplificati portatili. Un approccio statistico multivariato (chemiometria) \ue8 richiesto al fine di estrarre informazioni dal segnale acquisito, riducendo la dimensionalit\ue0 dei dati e mantenendo le informazioni spettrali pi\uf9 utili. Lo scopo del primo studio presentato \u2013 Testing of a Vis-NIR system for the monitoring of long-term apple storage \u2013 \ue8 la valutazione dell\u2019applicabilit\ue0 della spettroscopia nel visibile e vicino infrarosso (Vis-NIR) per il monitoraggio e la gestione delle mele durante lo stoccaggio a basse temperature. Per sette mesi \ue8 stata seguita l\u2019evoluzione in termini di grado zuccherino e consistenza delle mele suddivise in classi di maturazione. I risultati hanno indicato che la spettroscopia \ue8 una tecnica non-distruttiva che consente una stima accurata dei parametri chimico-fisici per la classificazione delle mele in lotti omogenei. Il lavoro descritto nel secondo paragrafo - Wavelength selection with a view to a simplified handheld optical system to estimate grape ripeness \u2013 \ue8 finalizzato all\u2019identificazione delle tre lunghezze d\u2019onda pi\uf9 importanti per il riconoscimento, direttamente in campo, dell\u2019uva pronta per essere raccolta al fine della messa a punto di un sistema semplificato e a basso costo. I coefficienti di regressione standardizzati del modello PLS (Partial Least Square) sono stati utilizzati per selezionare le variabili pi\uf9 importanti, che racchiudono l\u2019informazione pi\uf9 utile lungo l\u2019intero spettro. La stessa procedura \ue8 stata condotta per determinare la freschezza delle foglie di Valerianella durante la shelf-life - Selection of optimal wavelengths for decay detection in fresh-cut Valerianella Locusta laterr (terzo paragrafo). Lo scopo del lavoro presentato nel quarto paragrafo del primo capitolo - Comparison between FT-NIR and Micro-NIR in the evaluation of Acerola fruit quality, using PLS and SVM regression algorithms \u2013 \ue8 stimare l\u2019acidit\ue0 titolabile e il contenuto di acido ascorbico all\u2019interno del frutto acerola, utilizzando uno strumento compatto e a basso costo denominato Micro-NIR, che lavora nell\u2019intervallo spettrale 950-1650 nm. I dati spettrali sono stati modellati mediante l\u2019applicazione di due algoritmi PLS e SVM (Support Vector Machine). La capacit\ue0 predittiva dello strumento semplificato \ue8 risultata interessante per applicazioni di monitoraggio in campo, soprattutto modellizzando i dati in modo non lineare. Nel secondo capitolo, \ue8 presentata l\u2019applicazione di immagini RGB per la valutazione delle superfici - Image texture analysis, a non-conventional technique for early detection of biofilm. La texture dell\u2019immagine \ue8 definita come una differenza nella distribuzione spaziale, nella frequenza e nell\u2019intensit\ue0 dei livelli di grigio in ogni pixel dell\u2019immagine. Questo metodo \ue8 stato determinante per l\u2019identificazione precoce dello sviluppo microbico su superfici normalmente impiegate nell\u2019industria alimentare. L\u2019approccio chemiometrico \ue8 stato cruciale in ogni fase del progetto di dottorato ed \ue8 definito come un approccio statistico multivariato che si applica ai dati chimici per estrarre informazione utile, ridurre il rumore di fondo e l\u2019informazione ridondante. Il lavoro presentato all\u2019inizio del terzo capitolo - Hyperspectral image analysis: a tutorial - propone una procedura standard per l\u2019elaborazione di dati tridimensionali, presentando un esempio relativo alla predizione del raffermamento del pane in cassetta. Il secondo paragrafo del terzo capitolo, presenta una applicazione dell\u2019immagine iperspettrale su acerola, focalizzata sul contenuto di vitamina C - HSI for quality evaluation of vitamin C content in Acerola fruit. In questo lavoro, \ue8 stata acquisita l\u2019immagine di dieci acerola, raccolte in funzione del livello di maturazione, definito in base al colore della buccia (cinque acerola verdi e cinque rosse). Lo spettro della polvere di vitamina C pura \ue8 stato utilizzato come riferimento per l\u2019applicazione di due algoritmi di correlazione (spectral angle mapping e correlation coefficient), consentendo la costruzione di mappe qualitative di distribuzione dell\u2019acido ascorbico all\u2019interno del frutto. Lo scopo dell\u2019ultimo lavoro presentato \ue8 la valutazione della qualit\ue0 post raccolta dell\u2019acerola - Selection of NIR wavelengths from hyperspectral imaging data for the quality evaluation of Acerola fruit. Le immagini iperspettrali di venti acerola sono state acquisite per cinque giorni consecutivi. La valutazione delle modificazioni spettrali durante il tempo ha consentito la selezione delle tre lunghezze d\u2019onda caratterizzanti il processo di maturazione/degradazione del frutto. L\u2019immagine in falsi colori, derivante dalla composizioni delle immagini alle tre lunghezze d\u2019onda di interesse, consente l\u2019identificazione precoce del processo degradativo in maniera rapida e non distruttiva. Le tre tecniche non distruttive impiegate in questo progetto di dottorato hanno dimostrato efficienza e applicabilit\ue0 per la valutazione della qualit\ue0 e della sicurezza degli alimenti, rispondendo alla necessit\ue0 dell\u2019industria alimentare di tecniche accurate, veloci e obiettive per assicurare produzioni ottimali lungo l\u2019intero processo produttivo.This PhD project regards different applications of non-destructive optical techniques to evaluate quality and shelf life of agro-food product as well as the early detection of biofilm on food plants. Spectroscopy, image analysis and hyperspectral imaging could play an important role in the assessment of both quality and safety of foods due to their rapidity and sensitivity especially when using simplified portable devices. Due to the huge amount of collected data, chemometric, a multivariate statistical approach, is required, in order to extract information from the acquired signals, reducing dimensionality of the data while retaining the most useful spectral information. The thesis is organized in four chapters, one for each technique and a final chapter including the overall conclusion. Each chapter is divided in case studies according to the matrix analysed and the data acquisition and elaboration carried out. The first chapter is about spectroscopy. The aim of the first study - Testing of a Vis-NIR system for the monitoring of long-term apple storage - is to evaluate the applicability of visible and near-infrared (Vis-NIR) spectroscopy to monitor and manage apples during long-term storage in a cold room. The evolution of the apple classes, originally created, was analysed during 7 months of storage by monitoring TSS and firmness. Vis-NIR allows an accurate estimation of chemical-physical parameters of apples allowing a non-destructive classification of apples in homogeneous lots and a better storage management. The work reported in the second paragraph - Wavelength selection with a view to a simplified handheld optical system to estimate grape ripeness - is aimed to identify the three most significant wavelengths able to discriminate grapes ready to be harvested directly in the field. Wavelengths selection was carried out with a view to construct a simplified handheld and low-cost optical device. Standardized regression coefficients of the PLS model were used to select the relevant variables, representing the most useful information of the full spectral region. The same approach was followed to discriminate freshness levels during shelf-life of fresh-cut Valerianella leaves - Selection of optimal wavelengths for decay detection in fresh-cut Valerianella Locusta Laterr. (third paragraph). The aim of the work presented in the fourth paragraph of the first chapter - Comparison between FT-NIR and Micro-NIR in the evaluation of Acerola fruit quality, using PLS and SVM regression algorithms - is to estimate titratable acidity and ascorbic acid content in acerola fruit, using a MicroNIR, an ultra-compact and low-cost device working between 950 \u2013 1650 nm. The spectral data were modelled using two different regression algorithms, PLS (partial least square) and SVM (support vector machine). The prediction ability of Micro-NIR appears to be suitable for on field monitoring using non-linear regression modelling (i.e. SVM). In the second chapter, image analysis was performed. The traditional RGB imaging for the evaluation of image texture, a specific surface characteristic, is presented. The texture of an image is given by differences in the spatial distribution, in the frequency and in the intensity of the values of the grey levels of each pixel of the image. This technique was applied for the early detection of biofilm in its early stages of development, when it is still difficult to observe it by the naked eye, was evaluated (Image texture analysis, a non-conventional technique for early detection of biofilm). In the third paragraph, image and spectroscopy were combined in hyperspectral imaging applications. Data analysis by chemometric was crucial in any stage of my PhD project. Chemometric is a multivariate statistical approach that is applied on chemical data to extract the useful information avoiding noise and redundant data. At the beginning of the third chapter - Hyperspectral image analysis: a tutorial - proposes an original approach, developed as a flow sheet for three-dimensional data elaboration. The method was applied, as an example, to the prediction of bread staling during storage. The first application about hyperspectral on acerola is focused on the vitamin C content - HIS for quality evaluation of vitamin C content in Acerola fruit. Ten different acerola fruits picked up according to two different stages of maturity, based on the colour of the peel (5 green and 5 red acerola), were analysed. The spectra of pure vitamin C powder was used as references for computing models with two different correlation techniques: spectral angle mapping and correlation coefficient allowing the construction of a qualitative distribution map of ascorbic acid inside the fruit. The aim of the last one work presented is to evaluate acerola post-harvest quality - Selection of NIR wavelengths from hyperspectral imaging data for the quality evaluation of Acerola fruit. Hyperspectral images of 20 acerolas were acquired for five consecutive days and an investigation of time trends was carried out to highlight the most important three wavelengths that characterized the ripeness/degradation process of the Acerola fruit. The false-colour RGB images, derived from the composition of the three interesting wavelengths selected, data enable early detection of the senescence process in a rapid and non-destructive manner. In conclusion, the three non-destructive optical techniques applied in this PhD project have proved to be one of the most efficient and advanced tools for safety and quality evaluation in food industry answering the need for accurate, fast and objective food inspection methods to ensure safe production throughout the entire production process

Advances in Hydrogels

Hydrogels are a class of soft materials with crosslinked network structures. They show good biocompatibility, biodegradability, hydrophilicity, and mechanical properties similar to those of tissue, so they have a wide range of applications. In recent years, a variety of multifunctional hydrogels with excellent performance have been developed, greatly expanding the depth and breadth of their applications. This book is the reprint of the Special Issue “Advances in Hydrogels”, which focused on the recent advances regarding hydrogels, aiming to provide reference for researchers in related fields. This book included one editorial, thirteen original research articles, and three valuable reviews from thirteen different countries including Canada, China, Thailand, Mexico, India, Saudi Arabia, Chile, Germany, the Czech Republic, Colombia, Romania, Israel, and the USA

Characterising texture and cellular level responses of 'Centurion' blueberries during storage in different weight loss conditions : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Albany, New Zealand

Postharvest blueberry softening hinders consumer acceptance and correlates with high moisture loss during storage. Such textural variations have been attributed to factors such as turgor, cell wall modifications and other microstructural changes in the outer cell layers of the fruit. This thesis investigated the impact of moisture loss on blueberry quality, as well as the structure/function relationships associated with fruit texture characteristics during postharvest using an integrated physical and microstructural approach. Four different weight loss conditions (62%, 76%, 93% and 98% RH) were evaluated over a three week postharvest storage period to assess blueberry texture parameters using a texture analyser, where microstructural changes were assessed by light microscopy and optical coherence tomography (OCT). Under high weight loss conditions there was an increase in berry softening and a decrease in texture characteristics whereas an increase in berry firmness, hardness and gumminess was observed during storage under low weight loss conditions. Light microscopy clearly illustrated microstructural differences among ‘Centurion’ blueberries stored in different weight loss conditions, in retention of cell shape, degree of cell to cell wall contact, the amount of space between cells and cell wall integrity. When berries lost moisture during storage, epidermal and subepidermal cells retained their integrity, and parenchyma cells lost integrity leading to collapse which may contribute to overall fruit quality during postharvest. 3D OCT images showed no obvious differentiation between large cells at each weight loss treatment, however significant differences were observed in the microstructure between each storage period. In general the microstructure of medium to large cells in the parenchyma tissue showed an increase in average surface area and total surface area after each storage period. In summary, low weight loss storage conditions help to preserve blueberry texture and quality, whilst maintaining cellular structure and integrity during postharvest storage. It is recommended blueberries are stored between 95 – 99% RH and at a low temperatures to prevent moisture loss during postharvest

Fedco Seeds and Supplies 2020

When is a seed catalog more than a seed catalog? When it is the Fedco Seed catalog. Fedco, founded in 1978, is a worker-consumer cooperative in Maine known for promoting the ideals of cooperation, transparency, and the common ownership of seeds. These archives contain thousands of pages of Fedco’s seed catalogs. As one of its editors noted, “We give our readers things to think about.” Annual themes have included the role played by soil bacteria—the microscopic heroes that make life on this planet possible; the contributions of plant breeders and seed keepers; poetry by Walt Whitman, Vergil, and Russell Libby, among others. Editorials often stress the negative impact multinational corporations have on the genetic diversity of food crops, and provide annual updates on genetic engineering and the consolidation of the seed industry. Bits of humor are throughout, some of them in possibly the catalogs’ best feature: original art, and engravings from old seed catalogs and horticultural books. It is, in the words of Fedco’s founder CR Lawn, “More than a marketing tool.

Fedco Seeds 2021: Seeds and Supplies

When is a seed catalog more than a seed catalog? When it is the Fedco Seed catalog. Fedco, founded in 1978, is a worker-consumer cooperative in Maine known for promoting the ideals of cooperation, transparency, and the common ownership of seeds. These archives contain thousands of pages of Fedco’s seed catalogs. As one of its editors noted, “We give our readers things to think about.” Annual themes have included the role played by soil bacteria—the microscopic heroes that make life on this planet possible; the contributions of plant breeders and seed keepers; poetry by Walt Whitman, Vergil, and Russell Libby, among others. Editorials often stress the negative impact multinational corporations have on the genetic diversity of food crops, and provide annual updates on genetic engineering and the consolidation of the seed industry. Bits of humor are throughout, some of them in possibly the catalogs’ best feature: original art, and engravings from old seed catalogs and horticultural books. It is, in the words of Fedco’s founder CR Lawn, “More than a marketing tool.

Nanoparticules inorganiques luminescentes dopées aux lanthanides : synthèses, caractérisations et applications

Dans cette thèse, les nanoparticules d'oxysulfure et de fluorure de terres rares dopées au lanthanide sont explorées en tant que nanosondes pour des applications d'imagerie multimodale, de détection de température et d'imagerie temporelle. Le premier chapitre donne une brève introduction sur les nanoparticules susmentionnées et leurs propriétés optiques et leurs applications. Dans le chapitre 2, nous présentons une stratégie polyvalente pour la synthèse de 15 types de nanoparticules ultrapetites oxysulfure de terre rare (RE2O2S) d'une taille de 3 à 10 nm. Les NP Gd2O2S:Nd revêtues de PVP d'une taille de 6 nm sont synthétisées par une méthode d'échange de ligand. Nous démontrons que les NP Gd2O2S:Nd ultrapetites revêtues de PVP sont de bons agents de contraste en résonance magnétique pondérée (RM) T1 et T2, en tomodensitométrie (CT), en fluorescence dans le proche infrarouge (NIR-II) ainsi qu'en d'imagerie photoacoustique. Dans le chapitre 3, nous concevons une nouvelle hétérostructure cœur/coque dopé Ln3+. Des particules de Gd2O2S:20 %Yb,1%Tm ultra-petites (~ 5 nm) sont recouvertes d'une coque ß-NaYF4 optiquement inerte de ~ 4 nm par croissance épitaxiale, grâce au petit décalage de maille. Les nanoparticules à conversion ascendante Gd2O2S:20%Yb,1%Tm@NaYF4 core/shell UCNPs montrent une augmentation d'intensité de conversion ascendante de plus de 800 fois UCL par rapport à l'intensité du-coeur seul, une augmentation de durée de vie (transition 3H4 → 3H6 de Tm3+) de près de 1000 µs par rapport à 5 µs pour les cœur, et un rendement quantique de conversion ascendante jusqu'à 0,76 % à 155 W/cm2, ce qui est en concurrence avec d'autres UCNP à base de ß-NaYF4 avec des tailles similaires. Dans le chapitre 4, nous étudions le comportement thermique de la luminescence UC de nanoparticules Gd2O2S:20%Yb,1%Tm@NaYF4 et Gd2O2S:20%Yb,2%Er@NaYF4 cœur/coquille dans la plage de température de 293-473 K. Ensuite nous étudions comment la variation de la déformation du réseau influence le rapport de 4F9/2 → 4I15/2/4S3/2 → 4I15/2 de particules Gd2O2S:20%Yb,2%Er@NaYF4 avec une température variable. En outre, la sensibilité thermique relative record de 3,9% K-1 des particules Gd2O2S:20%Yb,1%Tm@NaYF4 est démontrée. Enfin, au chapitre 5, des objets cœur/coquille à conversion ascendante NaYF4:40%Gd,20%Yb,1%Tm@NaYF4:10%Yb@NaYF4:20%Nd,10%Yb sont synthétisés. Sur la base d'instruments optiques avancés, des spectres UCL à synchronisation temporelle et des durées de vie à 802 nm de Tm3+ sous une excitation laser de 808 nm sont mesurés, ce qui offre une possibilité théorique d'imagerie temporelle à l'aide des mêmes longueurs d'onde d'excitation et d'émission (~ 800 nm). Les conclusions et perspectives de ce travail sont explicitées dans le chapitre 6.In this thesis, lanthanide-doped rare earth oxysulfide and fluoride nanoparticles (NPs) are explored as nanoprobes for multimodal imaging, temperature sensing and time-gated imaging applications. The first chapter gives a brief introduction on the aforementioned nanoparticles and their optical properties and applications. In chapter 2, we present a versatile strategy for synthesis of 15 kinds of ultrasmall rare earth oxysulfide (RE2O2S) NPs with size of 3~10 nm. PVP-coated Gd2O2S:Nd NPs with size of 6 nm are synthesized through a ligand exchange method. We demonstrate that the ultrasmall PVP-coated Gd2O2S:Nd NPs are capable of T1 and T2 weighted magnetic resonance (MR), computed tomography (CT), second near infrared (NIR-II) fluorescence, photoacoustic, and ultrasound imaging. In chapter 3, we design a new Ln3+-doped core/shell heterostructure. ~5 nm ultrasmall Gd2O2S:20%Yb,1%Tm core is coated with ~4 nm optically inert ß-NaYF4 shell by epitaxial growth due to small lattice mismatch. The Gd2O2S:20%Yb,1%Tm@NaYF4 core/shell upconversion nanoparticles (UCNPs) show more than 800 times enhancement of upconversion luminescence (UCL) intensity compared to intensity of the core, lifetime (3H4 → 3H6 transition of Tm3+) of nearly 1000 µs compared to 5 µs of core, and upconversion quantum yield up to 0.76% at 155 W/cm2, which competes with other ß-NaYF4 based UCNPs with similar sizes. In chapter 4, we study UCL luminescence thermal enhancement behavior of Gd2O2S:20%Yb,1%Tm@NaYF4 and Gd2O2S:20%Yb,2%Er@NaYF4 core/shell UCNPs in the temperature range of 293-473 K. Then we further study how the variation of lattice strain influences the ratio of 4F9/2 → 4I15/2/4S3/2 → 4I15/2 of Gd2O2S:20%Yb,2%Er@NaYF4 core/shell UCNPs with varying temperature. Further, the highest relative thermal sensitivity of 3.9% K-1 of Gd2O2S:20%Yb,1%Tm@NaYF4 core/shell UCNPs is determined. In chapter 5, NaYF4:40%Gd,20%Yb,1%Tm@NaYF4:10%Yb@NaYF4:20%Nd,10%Yb core/shell/shell UCNPs are synthesized. Based on advanced optical instruments, time-gated UCL spectra and lifetimes at 802 nm of Tm3+ under 808 nm laser excitation are measured, which provide theoretical possibility for time-gated imaging using the same excitation and emission wavelengths (~800 nm). Conclusions and perspectives for this work are elucidated in chapter 6