In food manufacturing, the quality control procedure is a critical activity that consists in organizing, measuring, tracking, and filing the conditions of the production process and the final product, with the goal of guaranteeing the designed quality standard. During the last 30 years, due to a mounting concern by both consumers and lawmakers, the definition of quality and the application of quality control improved drastically, and new methodologies have been developed to ensure better control of food production and to understand the effect of raw materials and the process condition on the final quality of the food product. This thesis discusses the approaches to quality control procedures in food manufacture, focusing on the relationship between the conditions of the process and the quality profile of the final product, testing in a real-case scenario of a complex production process advanced data analysis procedures. The statistical and analytical procedures proposed have been applied in a real case studio from Trentingrana cheese production, a dairy consortium in the northeast region of Italy producing a ripened semi-artisanal hard cheese under the Protected Denomination of Origin (PDO) of Grana Padano. The aim is developing tailored statistical procedures that infer the effect of the critical factors of production on quality properties of this PDO product considering its semi-artisanal production process and the presence of multiple confounding factors. The statistical analyses were applied to a dataset of measurements of physical, sensory, and chemical properties collected on cheese wheels sampled systematically to represent the variability of the production of the Trentingrana wheels over two years of production. In the first introductory chapter, after a review of the different definitions of quality, the most important quality parameters for a food product and the standard measurement techniques adopted in quality control are presented. Then, in the chapter 2, the standard procedures of data analysis are reviewed, as well as the new approaches derived from the context of the foodomic sciences and machine learning models for the analysis of quality control data in food manufacturing. Two implemented and tested practical statistical procedures in the context of the Trentingrana consortium are reported: the results are discussed according to the objectives of the quality control process, the type of data, and the organization of food production. In the first case, reported in chapter 3, Linear Mixed Model ANOVA Simultaneous Component Analysis (LMM-ASCA) was developed to investigate the effect of the dairy factory, the bimester of production, and the variability within a cheese wheel using colorimetric and textural measurements. In the second case, reported in chapter 4, a standard ASCA model with the addition of a blocking factor to include systematic error was developed to investigate the relationship between the dairy factory and bimester of production and the volatile organic compounds (VOCs) profile of Trentingrana cheese wheels. In addition, in chapter 5, an approach to relate physical measurements on Trentingrana samples with sensory evaluations of texture by a trained panel is presented. The objective of this procedure is to incorporate the quality control procedure information from different quality parameters. The development of the Partial Least Squares (PLS) predictive model, its validation, and the evaluation of its performances are discussed. In the last section (chapter 6), the development of an image analysis procedure to measure the visual quality of the rind thickness of cheese wheels is reported, comparing the performances of two different algorithms. The data analysis tools proposed in this thesis have been proved to be useful for exploring, inferring, and plotting the process quality properties and suitable for analyzing complex and unbalanced experimental designs. Furthermore, the data analysis procedures proposed improve quality control activity both at the process level and at the product level, increasing the information that is possible to extract from the measurement collected in a context where standard statistical approaches cannot infer significant information.

Combining foods, combining tools. To date, most of the published works that have attempted to relate aroma release and sensory perception are far from mimicking the real consumption context, as assessments often do not consider food oral processing during mastication and are performed on single or model foods. A multidisciplinary approach integrating in vivo aroma release, oral processing behaviour, and dynamic sensory methods is needed to have a better understanding of how the release, evolution, and fading of the flavour of real complex food matrices are being perceived during consumption. The research described in this thesis aims to investigate the relative contributions that food structure and its composition and oral processing behaviour have on aroma release and perception of food matrices made up of different components and contrasting textures, so-called composite foods. Results showed that the processes of aroma release and perception of composite foods are multidimensional phenomena and seem to be modulated by cross-modal texture-aroma interactions. While aroma release increased when a food was assessed in combination with other foods, consumer’s ability to discriminate between foods was reduced and off-flavours and texture deficiencies were masked. Furthermore, the role of oral processing behaviour on the breakdown of the food impacting aroma release and perception was highlighted. The use of a multidisciplinary approach provided more useful and accurate sensory profile representing an ecological, valid food consumption context that will ultimately offer new strategies for successfully developing healthier food products with lower fat and sugar content or elaborated with plant protein, for which sensory acceptability remains a challenge.

Per via degli svantaggi inerenti l’uso di bentonite nella produzione di vini bianchi, la ricerca di alternative ha assunto di recente una grande importanza. Il lavoro presentato in questa tesi ha l’obiettivo di valutare l’applicabilità di tre approcci innovativi alla stabilizzazione colloidale dei vini: l’uso di chitosano, l’applicazione dei PEF e il riutilizzo di colonne di scambio cationico. L’aggiunta di chitosano è risultata nella rimozione delle chitinasi dal vino, permettendo di raggiungere un soddisfacente livello di stabilità. Gli effetti sul colore e sugli aromi, quando non significativi, non sono risultati essere peggiori rispetto ai risultati ottenuti da trattamenti con bentonite. L’applicazione dei PEF aveva lo scopo di innescare la denaturazione e l’aggregazione delle proteine tramite un sistema di trattamento-raffreddamento e filtrazione finale. I risultati suggeriscono che un buon grado di stabilità viene raggiunto solo con trattamenti particolarmente energetici ma questo a danno del colore del prodotto. Infine, lo scopo dello studio sulle resine di scambio cationico era quello di valutare la rigenerazione di questo supporto per un molteplice utilizzo operativo. La rimozione delle proteine adsorbite sul supporto è risultata essere possibile in specifiche condizioni di pH e forza ionica, con un consumo di acqua relativamente basso. / The search for fining alternatives to bentonite has assumed great importance in white winemaking due to the drawbacks of bentonite application. The research here presented aimed at observing the viability of three innovative approaches to wine stabilization, namely chitosan addition, PEF treatments and cation exchange applicability. Chitosan successfully removed chitinases from wine, allowing at the same time a sufficient degree of colloidal stability. Collateral effects on color and aroma compounds were non-significant or acceptable when compared with the effects observed for bentonite applications reported in literature. The use of PEF was aimed at accelerating protein unfolding and aggregation and was coupled to an in-line cooling and filtration system for efficient removal of colloidal aggregates. The results collected suggested that the treatment was capable of inducing a satisfactory colloidal stability only in high- energetic double-treated wine samples, with some deleterious consequences on the color. Finally, the aim of the research for cation-exchange resins application was to find environmentally friendly cleaning procedures to regenerate the resin capacity and allow reuse of the same resin for further cycles of fining. The removal of proteins bound to the resin was possible under specific pH and ionic strength conditions with relatively low consumption of water.

Lo scopo del presente lavoro è stato quello di esaminare il potenziale di idrolisi e degradabilità dell’amido dei cereali e co-prodotti e di valutare gli aspetti collegati. L’approccio utilizzato comprende sia test in vitro che in vivo. In particolare: - Una serie d’indagini in vitro ha fornito dati sul potenziale di degradabilità enzimatica dell’amido dei cereali e co-prodotti considerando sia l’influenza della struttura dell’amido, del tipo di cereale, del rapporto amilosio:amilopectina, del processo termico, dell’insilamento, dello stadio di maturazione e delle pratiche agronomiche. - Una valutazione funzionale basata sul calcolo del potenziale di degradabilità enzimatica dell’amido tramite la stima dell’indice glicemico in vitro, combinata con un approccio matematico di modellizzazione dei dati ottenuti, è stata proposta per fornire un metodo efficace di screening dei materiali amidacei utilizzati comunamente nella formulazione per diete destinate ai suini. - Un esperimento in vitro è stato condotto per investigare la risposta glicemica post-prandiale in suini alimentati con diete che differivano nel potenziale di idrolisi enzimatica. Infine, considerando la crescente attenzione dei nutrizionisti sulla matrice proteica dei cereali (con particolare importanza data alle prolammine), i metodi comunemente utilizzati per le tecniche di estrazione delle prolammine sono stati confrontati e ri-investigati. / In the present work, it has been attempted to examine the variability in starch hydrolysis and digestion from cereal grains and co-products and to study aspects related, in order to give a better understand of the science behind the differences in grains/feeds starch digestion potential. The general approach was to use a combination of in vitro and in vivo techniques. In particular: - A series of in vitro investigations has provided data on the degradation potential of starch from cereal grains and co-products considering the influence of starch structure, cereal type, amylose-amylopectin ratio, heat processing, ensiling, stage of maturity and of agricultural practices. - A laboratory-based functional evaluation of starch value of cereal grains based on a predicted glycemic index approach, combined with a mathematical first-order exponential model, has been proposed in order to allow an efficient screening of starchy-materials entering in the pig diet formulation. - An in vivo experiment has been undertaken to investigate the postprandial plasma glucose response in pigs fed diets containing starch with a wide range in in vitro digestion patterns. Lastly, taking into account the increasing attention of swine nutritionists on prolamin proteins, the most commonly used prolamin extraction procedures were compared and reinvestigated, in order to get useful information for routine lab analysis.

Attualmente il gusto di tappo è uno dei problemi più gravi per il settore enologico e sugheriero. I principali composti responsabili di questo difetto sono i policloroanisoli, tra cui in particolare il 2,4,6-tricloroanisolo (TCA),che si formano dai corrispondenti precursori fenolici. La ricerca ha preso in esame vari aspetti:-studio dell'impatto sensoriale del TCA in diversi tipi di vino;-ottimizzazione di metodi di estrazione e analisi di policlorofenoli e policloroanisoli nel sughero e nel vino;-studio della microflora presente nel sughero in base alla capacità di degradare i policlorofenoli. I risultati hanno mostrato che l'uso di un unico valore soglia per la percezione del TCA nei vini non sembra idoneo; i metodi messi a punto sono risultati adeguati per la determinazione di clorofenoli e cloroanisoli; i microrganismi hanno presentato una capacità di produrre TCA differente a seconda del ceppo utilizzato. / Today cork taint is one of most serious problems for wine and cork industries. The primary compounds considered responsible for this defect are chloroanisoles, especially 2,4,6-trichloroanisole (TCA), that are produced from their phenolic precursors. The PhD work was carried out studying different aspects of this subject: -effect of wine style on the perception of TCA;-optimization of extraction and analysis methods to determine chlorophenols and chloroanisoles in wine and cork; biodegradation ability of mould isolated from cork to produce TCA from TCP. The results showed that the use of generic threshold values for all wines does not seem to be accurate enough; methods optimized are adequate to detect chlorophenols and chloroanisoles; micro-organisms tested can produce TCA from TCP.

La presente attività di ricerca ha avuto come oggetto di studio la formazione di biofilm in condizioni dinamiche: per raggiungere tale obiettivo, è stato costruito un idoneo apparato che permettesse di ottenere una valutazione quantitativa sia delle cellule presenti nella soluzione di crescita sia di quelle adese su tre materiali di prova(acciaio inossidabile, PET e rame). Oltre ad esprimere una valutazione dell’adesione batterica alle superfici, si è proceduto ad indagare sui possibili parametri sperimentali che potessero influenzare la formazione di biofilmdi Listeria su superfici abiotiche. Allo stesso tempo l’efficacia battericida di alcuni biocidi è stata valutata sulle cellule planctoniche così come su biofilm batterici sviluppati su superfici abiotiche. Il ruolo del sistema di quorum sensing basato su luxS nella formazione di biofilm batterici: un ceppo di L. innocua con buone capacità adesive è stato confrontato con il suo ceppo deficiente di luxS per la sua suscettibilità ad agenti biocidi così come per la sua capacità di adesione superficiale L’effetto della precendentemente menzionata inattivazione genetica sulla cinetica di crescita batterica e, quindi, sull’efficienza metabolica complessiva è stata esaminate mediante lo strumento BioscreenC. L’effetto inibitorio di due composti polifenolici è stato valutato sul ceppo deficiente di luxS così come sul ceppo originale. / The current research activity was focused on biofilm formation in dynamic conditions. A suitable device was thus constructed, in order to have a quantitative evaluation of the cells freely suspended in the flowing nutrient solution used as well as the sessile cells which adhered on the three tested surfaces (stainless steel, polyethylene therephthalate and copper). During this project, other than of a quantitative assessment of bacterial adhesion, we investigated also on the parameters which could affect significantly the biofilm formation of Listeria on abiotic surfaces. At the same time antimicrobial efficiency of selected biocides was investigated on planktonic cells as well as on bacterial biofilms grown on abiotic surfaces. The role of luxS-based quorum sensing system in the biofilm development process was evaluated: a luxS-null mutant of an adhesive strain of L. innocua was obtained through Campbell-like genetic inactivation and then evaluated for its sensitivity to biocidal agents and adhesion to surfaces, in comparison with its parental strains. Furthermore the effect of genetic inactivation on bacterial growth kinetic and thus on overall bacterial metabolic efficiency was assessed through the apparatus of BioscreenC. Finally two polyphenolic compounds were investigated for their inhibitory effect on Listeria.

While consumer awareness of benefits of adequate nutrition has noticeably surged in recent years, developing countermeasures against improper eating habits still represents a public health priority in view of the growing prevalence of diet-related diseases. Eating behaviours are complex phenomena driven by a spectrum of biological and environmental factors, wherein (chemo)sensory perception is reckoned amongst the most influential. Analogously, chemosensation is affected by a myriad of determinants, and this warrants the commonly observed large variation in how tastes and smells are perceived among individuals. Given how such variability intimately relates to dietary habits, deciphering its underlying mechanisms is paramount to promoting healthier food choices. In this vein, emerging evidence suggests that human eating behaviours can also be affected by interactions between the gastrointestinal microbiota and the chemosensory systems. Despite growing interest, the sensory-oriented microbiome field suffers from obvious limitations due to its recent emergence. As a result, little efforts has been devoted to elucidating: a) the associations between the oral microbiota and olfaction or known psychological mediators of sensory perception; b) the links between the distal gut microbiota and taste functioning; c) the consequences of interactions between chemosensation and the gastrointestinal microbiota on dietary intakes. Against this backdrop, this thesis aimed at expanding the current knowledge on the interplays between domains of sensory perception and the gastrointestinal microbiota and how these might mirror variations in habitual food habits. In detail, four studies probing the associations a) between a psychosocial correlate of sensory perception (food neophobia), olfaction (Chapter 2) and the oral microbiota (Chapter 3); and b) between distal gut (Chapter 4) or oral (Chapter 5) microbiota, taste functioning and dietary intakes are here presented. In Chapter 2 and 3, a healthy cohort of 83 individuals (57.8 % women; aged 22-68 yo) remotely filled out the common Food Neophobia Scale and the trait anxiety subscale of the State-Trait Anxiety Inventory prior to providing a salivary sample for subsequent metataxonomic analysis (16S rRNA gene sequencing). Next, volunteers were tested for orthonasal olfactory functioning via the Sniffin’ Sticks battery, and monitored for retronasal aroma release while consuming a strawberry jelly candy by nose-space analysis (Selected-Ion Flow-Tube Mass Spectrometry). In Chapter 4 and 5, instead, 100 young adult volunteers (52 % women; aged 18-30 yo) attended a 7-day lasting remote protocol where responsiveness to genetically-mediated bitterness of 6-n-propylithiuracil (PROP), hedonics and intensity of oral sensations elicited by ten commercially-available food products, a battery of food-related psychological traits, a 4-day food record, and one salivary and one stool sample (sequenced by targeting the 16s rRNA gene) were collected. Overall, results substantially strengthen past evidence suggesting: a) that pronounced neophobic tendencies translate into higher levels of (negative) emotional activation or arousal towards foods; b) the existence of homogenous groups of individuals with generalized hypergeusia towards oral stimulations; c) that hyperresponsiveness to a peculiar taste quality is a barrier to the intake of foods evoking such sensation; d) that habitual consumption of dietary fibers and simple carbohydrates can shape both the gut and oral microbial ecology, respectively. Intriguingly, food neophobia and poor olfaction were positively associated with oral microbial markers of dysbiosis (e.g., Porphyromonas gingivalis), whilst a Clostridia-enriched salivary microbiota co-occurred with low responsiveness to alarming oral sensations (astringency, bitter, sour) elicited by real foods. Similarly, an ample panel of commensal gut bacterial genera mainly allocated to the families Lachnospiraceae and Ruminococcaceae was found to be enriched in individuals exhibiting lower acuity to both tastes (bitter, salty, sour, sweet) and trigeminal sensations (astringent, pungent). Besides taxonomically annotating a range of microbial taxa tied to sensory perception, putative metabolic pathways used by salivary and gut microbial communities to modulate taste perception were inferred and discussed. To conclude, this thesis supports the notion that the gastrointestinal microbiota is an additional candidate to explain interindividual variations in taste and smell perception, and provides novel important insights into the aetiology of eating behaviours. More importantly, this work also offers methodological cues to robustly assess the associations between chemosensation and host-related non genetic factors, and paves the way for future interventional studies targeting the efficacy of sensory-related microbial taxa as potential modulators of dietary habits.

Durante la mia tesi di dottorato ho selezionato nuovi potenziali ceppi probiotici, combinando l'approccio convenzionale con l’utilizzo di piattaforme di nuova concezione. Mi sono concentrata inizialmente sul cosiddetto "screening tradizionale" finalizzato all'isolamento di nuovi ceppi batterici di lattobacilli e bifidobatteri e alla valutazione della loro sicurezza per il consumo umano e della loro efficacia. I ceppi selezionati sono stati quindi sottoposti ad uno screening più specifico, a seconda dell'applicazione a cui sarebbero stati destinati. In questa fase sono stati utilizzati sia test in vitro che modelli animali, al fine di valutare l'applicabilità dei ceppi di recente selezionati come probiotici per la promozione della salute umana e il loro possibile impiego in campo alimentare. Ho valutato il potenziale utilizzo dei ceppi nell’integrazione alimentare di soggetti che seguono diete ad alto contenuto proteico per ridurre il rischio di accumulo intestinale di ammine biogene, e ho individuato un ceppo di Lactobacillus con presunta attività ammino-degradativa. L'obiettivo principale di un’altra attività di screening è stato lo studio degli effetti immunomodulanti di nuovi ceppi: combinazioni di probiotici sono risultati buoni candidati per il trattamento delle malattie infiammatorie e autoimmuni (miastenia grave e sclerosi multipla) nel modello di topo. Infine, i ceppi sono stati sottoposti a screening per una potenziale applicazione in campo alimentare, finalizzata ad indagare la possibilità di produrre formulazioni di probiotici “atomizzati” da utilizzare insieme alla base commerciale del gelato. / During my PhD thesis I screened new potential probiotic strains by combining conventional approach to newly designed platforms. I focused first on the so-called "conventional screening” aimed to the isolation of new bacterial strains of lactobacilli and bifidobacteria and to assess their safety for human consumption and their efficacy by in-vitro methods. Selected strains were then submitted to a targeted screening by specifically designed models, depending on the application to which they would be destined. These models combined in vitro tests and animal models in order to assess the applicability of newly selected strains as probiotics for the promotion of human health and their possible use in food field. I evaluated the potential use of strains in the food supplementation of subjects that follow high-protein diets to reduce the risk of intestinal accumulation of biogenic amines, and I identified a strain of Lactobacillus with alleged amino degradative activity. The main objective of another screening activity was the study of the immunoregulatory effects of new strains: combinations of probiotics resulted good promising candidates for the treatment of inflammatory and autoimmune diseases (myasthenia gravis and multiple sclerosis) in rat model. Finally, strains were screened for a potential application in food field, in order to investigate the possibility of producing spray-dried probiotic formulations to be used together with commercial ice-cream bases.

L’utilizzo degli scarti da parte dell’industria alimentare costituisce una sfida importante per ridurre le perdite di cibo, aumentare la sostenibilità della produzione alimentare e, pertanto, incrementare la sicurezza alimentare specialmente nei paesi in via di sviluppo. Obiettivo della presente tesi è ottenere aceto dagli scarti dell’ananas tramite idrolisi enzimatica preceduta da pre-trattamento fisico, fermentazione alcolica con differenti ceppi di Saccharomyces cerevisiae, addizionati di Lactobacillus delbruekii o Lactobacillus plantarum del liquido saccarificato, e fermentazione acetica con Acetobacter aceti in un impianto pilota. I campioni ottenuti dalle prove di saccarificazione, fermentazione alcolica e acetica sono stati analizzati per pH, acidità totale, grado Brix, zuccheri, acidi organici, etanolo e per i composti volatili. Una caratterizzazione dettagliata dell’aceto è stata eseguita tramite UPLC/Q-TOF e GC-MS. / Using waste from the food industry is a major challenge to reduce food losses, to increase the sustainability of food production and, therefore, increase food security, especially in developing countries. The objective of this thesis is to get vinegar from pineapple waste by means of: enzymatic hydrolysis proceeded by physical pre-treatment; alcoholic fermentation of the saccharified juice with different strains of Saccharomyces cerevisiae and Lactobacillus delbruekii or Lactobacillus plantarum; acetic fermentation with Acetobacter aceti in a pilot plant. Samples obtained from saccharification, alcoholic and acetic fermentation were analyzed for pH, total acidity, total soluble solid (TSS), sugars, acids, ethanol, and volatile compounds. A detailed characterization of vinegar was carried out through UPLC/Q-TOF and GC-MS.

La tesi di dottorato è stata sviluppata all'interno del progetto nazionale Valorvitis ed è suddivisa in due parti. La prima riguarda la caratterizzazione chimica di sei estratti di vinacce d’uva ottenute diverse varietà di uva: tre a bacca rossa( Pinot Noir, Barbera e Nebbiolo) e tre a bacca bianca (Moscato, Muller Thurgau e Chardonnay). Ogni estratto è stato caratterizzato per contenuto e composizione in composti fenolici. La seconda attività consiste nello studio di un metodo alternativo di estrazione-purificazione basato sull'impiego di Gas Aphron Colloidali (CGAs) con la finalità di ridurre i costi di processo, la quantità di solvente da utilizzare durante la fase di estrazione e, allo stesso tempo, aumentare il grado di purezza dell’estratto in termini di contenuto polifenolico. / The present PhD thesis work was carried out under the framework of the Valorvitis.Extracts have been obtained from different red (Pinot Noir, Barbera and Nebbiolo) and white (Moscato, Muller Thurgau and Chardonnay) grape marcs and quantitatively analysed for the content of total phenolics, tannins, anthocyanins, cinnamic acids, flavonoids, flavonols, sugars (glucose and fructose) and for the anti-oxidant power (AOP). A new extraction-purification process based on CGAs application has been investigated. CGAs were first reported by Sebba (1987) as micro bubbles, with dimension among 10–100 μm, composed of a gaseous inner core surrounded by a thin surfactant film, which are created by intense stirring of a surfactant solution above its critical micellar concentration. Surfactants are able to catch phenolics thanks to both electrostatic and hydrophobic interactions depending on the surfactant (ionic or non-ionic) and on the phenolic compound. In this project the low-cost non-ionic food grade surfactant Tween 20 was used.