Essays on Consumer Demand Marketing and Policy Implications from Primary and Secondary Data

This dissertation focuses on analyzing consumer demand for agricultural products and explores its marketing and policy implications by utilizing both primary and secondary data. The first chapter delves into estimating consumers' willingness to pay for attributes such as sugar content, CRISPR technology, and cranberry flavor intensity in two cranberry products, each presented with different health-related information treatments. Respondents expressed a preference for reduced sugar content over regular sugar products, for conventional over CRISPR breeding methods, and for full/intense cranberry flavor over weak/bland flavor. Interestingly, information emphasizing cranberries' health benefits and sugar intake recommendations amplified the reject to reduced sugar content, surpassing the reject to CRISPR.In the second paper, a Basket-Based Choice Experiment was employed to identify sensory and hedonic quality descriptors of fresh blueberries that could potentially increase the likelihood of purchase. The findings revealed that blueberry packages with a "Stay Fresh" descriptor had a lower price elasticity compared to packages without descriptors or those with "Sweety" and "Crunchy" descriptors. This suggests that consumers are less responsive to price fluctuations when blueberry packages include language indicating an extended shelf life. Moreover, the study indicated that strawberries, blackberries, raspberries, and blueberries are more likely to be purchased together rather than considered substitutes. Additionally, the research identified specific demographic and behavioral factors associated with a higher likelihood of choosing blueberries from a selection of commonly consumed fruits.In the third paper, weekly shipment data from nine apple varieties in Washington state were analyzed to assess the predictive capabilities of various time series models. While some traditional time series models, specifically the Seasonal Autoregressive Integrated Moving Average, excelled in predictive accuracy and capturing variability, this study recommends the use of a machine learning model, specifically Facebook Prophet, due to its computational efficiency and strong predictive accuracy. Additionally, the research explored the impact of introducing a new apple variety, Cosmic Crisp®, on the shipments of existing apple varieties using an interrupted time series analysis. The influence of this introduction varied among different apple cultivars, with some experiencing no changes while others experiencing a decline in subsequent shipment levels. Notably, the overall apple shipments in Washington State remained unaffected by the introduction of Cosmic Crisp®. We also found that the shipments of Cosmic Crisp® stimulates the supply of specific apple varieties and the overall apple supply

Non-volatile Bioactive and Sensory Compounds in Berries and Leaves of Sea Buckthorn (Hippophaë rhamnoides)

Sea buckthorn (Hippophaë rhamnoides L., SB) is regarded as a raw material of high economic value and a source of many health-related bioactive compounds, such as flavonol glycosides (FGs), proanthocyanidins (PAs) and ethyl β-Dglucopyranoside (EG) in berries and ellagitannins (ETs) in leaves. These phenolic compounds are also well known components in various foods inducing astringent and bitter sensations. Ethyl β-D-glucopyranoside, an alkylated glucose, is among the major chemotaxonomic characteristics in SB berries. The aims of the current work were: 1) To qualitatively and quantitatively analyze FGs, PAs in SB berries and purees, as well as FGs and ETs in SB leaf and leaf tea-type beverages; 2) To determine the effects of genetic background, growth sites and processing methods on the contents and compositions of these compounds; 3) To investigate the roles of FGs, PAs and EGs in the sensory quality of SB purees/juices; 4) To study the antioxidant activities (AAs) in leaf tea-type infusions, the correlations with AAs, FGs and ETs. Twenty-six flavonol glycosides with isorhamnetin and quercetin as the major aglycones were found in the wild SB (ssp. sinensis) berries from China and cultivated berries (ssp. mongolica) from Finland and Canada. The contents of FGs varied from 23 to 250 mg/100 g fresh berries, which were significantly higher in ssp. sinensis than in ssp. mongolica. The berries of ‘Oranzhevaya’ and ‘Prevoshodnaya’ had the lowest (23 mg/100 g) and the highest content of FGs (80 mg/100 g), respectively. The samples from Kittilä (North Finland) had higher levels of most FGs than those from Turku (South Finland) and Québec (Canada). Among the ssp. sinensis berries, the berries from Sichuan had the highest contents and unique profiles of FGs. Increasing trends were detected in the contents of most FGs as the altitude increased and as the latitude decreased. The role of ethyl β-D-glucopyranoside was investigated in the sensory profiles of SB juices of ‘Terhi’ and ‘Tytti’. The taste threshold of pure EG was estimated in water solution as 1.1 ± 1.3 g/L, and the suprathreshold aqueous EG solution (5.0 g/L) was perceived mainly as bitter. Addition of EG increased bitterness of SB juice, which correlated with the EG content, as well as with the ratios of EG/acids and EG/sugars. The roles of FGs and PAs were also investigated in purees of six SB cultivars. The sensory profiles of the purees were dominated by intense sourness due to abundant malic acid, followed by astringency and bitterness. Malic acid and isorhamnetin glycosides related strongly to the astringency, whereas PA dimers, PA trimers and quercetin glycosides had less influence. Moreover, the acids/phenolic compounds ratios were more important predictors of bitterness than the individual variables alone. Composition and contents of flavonol glycosides and ellagitannins as well as antioxidant activities were investigated in tea-type infusions processed from sea buckthorn leaves using different drying methods. These infusions had high content of phenolic substances together with associated strong antioxidant activities, were considerably acceptable for consumers. Isorhamnetin-3-Oglucoside- 7-O-rhamnoside, isorhamnetin-3-O-rutinoside and kaempferol-3-Ohexoside- 7-O-rhamnoside were the three major FGs, and stachyurin and casuarinin were the most abundant ETs in all the samples. Significant differences were found in the contents of most ETs between the infusions of ‘Terhi’ and ‘Tytti’ (p < 0.05). The ET contents varied significantly among the different processing methods, whereas less effect was seen on the FGs contents. Thermal processing decreased the antioxidant activities of the infusions. Additionally, significant contents of phenolic compounds were left in the leaf residues after the hot water extractions.Tyrni (Hippophaë rhamnoides L.) on taloudellisesti tärkeä elintarvikkeiden raaka-aine. Sen marjat ovat monien terveyteen vaikuttavien bioaktiivisten yhdisteiden, kuten flavonoliglykosidien (FG), proantosyanidiinien (PA) ja etyyli-β-D-glukosidin lähde, ja kasvin lehdissä on runsaasti ellagitanniineja. Nämä fenoliset yhdisteet ovat myös tunnettuja astringoivaa suutuntumaa ja karvautta aikaansaavina komponentteja monissa elintarvikkeissa. Etyyli-β-Dglukosidi, alkyloitunut glukoosi, on yksi tyrnin marjojen merkittävimmistä, tunnusomaisista kemotaksonomisista yhdisteistä. Tämän tutkimuksen tavoitteina oli 1) määrittää laadullisesti ja määrällisesti FG:t ja PA:t marjoista ja soseista sekä FG:t ja ET:t lehdistä ja lehdistä valmistetuista teenkaltaisista juomista, 2) määrittää perinnöllisen taustan, kasvupaikan ja käsittelymenetelmien vaikutukset yhdisteiden määriin ja koostumukseen, 3) tarkastella FG:ien, PA:ien ja EG:n merkitystä soseiden ja mehujen aistittavalle laadulle ja 4) tutkia lehdistä valmistettujen teenkaltaisten juomien antioksidanttiaktiivisuutta (AA) ja yhteyksiä AA:ien ja FG:ien sekä ET:ien välillä. 26 flavonoliglykosidia, joiden pääasialliset aglykonit olivat isoramnetiini tai kversetiini, havaittiin luonnonvaraisista kiinalaisista tyrneistä (alalaji sinensis) ja viljellyistä suomalaisista ja kanadalaisista tyrneistä (alalaji mongolica). Yhdisteiden kokonaispitoisuudet vaihtelivat tuoreissa marjoissa välillä 23 ja 250 mg/100 g. Pitoisuudet olivat merkitsevästi suuremmat sinensis-alalajin kuin mongolica-alalajin marjoissa. ”Oranzhevaya”-lajikkeesta löytyi pienin (23 mg/100 g) ja ”Prevoshodnaya”-lajikkeesta suurin pitoisuus (80 mg/100 g) flavonoliglykosideja. Kittilän (Pohjois-Suomessa) näytteissä useimpien FG:ien pitoisuudet olivat korkeampia kuin Turun (Etelä-Suomessa) tai Quebecin (Kanada) näytteissä. Sichuanin (Kiina) näytteissä oli suurin FG-pitoisuus ja yksilöllisin koostumus yhdisteitä. Useimpien FG-yhdisteiden pitoisuus kasvoi altitudin kasvaessa tai leveysasteen pienentyessä. EG:n merkitystä aistittavaan laatuun tarkasteltiin ”Terhi”- ja ”Tytti”- lajikkeista valmistetuissa mehuissa. Puhtaan EG:n makukynnykseksi vedessä määritettiin 1,1 ± 1,3 g/L ja kynnystä korkeamman pitoisuuden (5,0 g/L) vesiliuos aistittiin pääasiassa karvaana. EG:n lisäys nosti tyrnimehun karvautta, mikä korreloi EG:n pitoisuuden sekä EG:n ja happojen ja EG:n ja sokerien pitoisuuksien suhteiden kanssa. FG:ien ja PA:ien merkitystä tarkasteltiin kuudesta tyrnilajikkeesta valmistetuissa soseissa. Soseiden aistittavan laadun profiilia hallitsi voimakas omenahaposta johtuva happamuus sekä seuraavina astringoivuus ja karvaus. Omenahappo ja isoramnetiinin glykosidit olivat yhteydessä astringoivuuteen kun puolestaan PA:n dimeerit tai trimeerit sekä kversetiinin glykosidit olivat vähemmän merkittäviä. Lisäksi happojen ja fenolisten yhdisteiden suhde oli merkittävämpi karvautta ennustava tekijä kuin yksittäiset muuttujat yksinään. Tyrnin lehdistä erilaisilla kuivausmenetelmillä valmistetuista teentyyppisistä haudukkeista tarkasteltiin flavonoliglykosidien ja ellagitanniinien koostumusta ja pitoisuuksia sekä antioksidatiivisia vaikutuksia. Kuluttajat kokivat haudukkeet hyväksyttäviksi. Niissä oli korkeita pitoisuuksia antioksidatiivisuuteen yhdistettyjä yhdisteitä. Isoramnetiini-3-O-glukosidi-7-O-ramnosidi, isoramnetiini-3-O-rutinosidi ja kemferoli-3-O-heksosidi-7-O-ramnosidi olivat merkittävimmät FG:t ja stakyuriini ja kasuariini olivat merkittävimmät ET:t kaikissa näytteissä. Tyrnilajikkeista valmistettujen haudukkeiden välillä oli merkitseviä eroja useimpien ET:ien pitoisuuksissa, jotka vaihtelivat merkitsevästi eri käsittelymenetelmien välillä, kun taas FG:ien pitoisuuksiin menetelmillä oli vähemmän vaikutusta. Lämpökäsittely vähensi haudukkeiden antioksidatiivista aktiivisuutta. Lisäksi merkittäviä pitoisuuksia fenolisia yhdisteitä jäi lehtien jäännöksiin kuumavesiuuton jälkeen

Health promoting properties and sensory characteristics of phytochemicals in berries and leaves of sea buckthorn (Hippophaë rhamnoides)

Sea buckthorn (Hippophaë rhamnoides L., SB), as a multi-functional plant, is widely grown in Asia, Europe and Canada. The berries and leaves of SB contain a diverse array of health-supporting phytochemicals, which are also related to the sensory qualities of berry and berry products. This review summarizes the biologically active key-compounds of the berries and leaves of SB, their health-promoting effects, as well as the contributions to the sensory quality of the berries. The target compounds consist of sugars, sugar derivatives, organic acids, phenolic compounds and lipophilic compounds (mainly carotenoids and tocopherols), which play an important role in anti-inflammatory and antioxidant functions, as well as in metabolic health. In addition, these compounds contribute to the orosensory qualities of SB berries, which are closely related to consumer acceptance and preference of the products. Studies regarding the bioavailability of the compounds and the influence of the processing conditions are also part of this review. Finally, the role of the sensory properties is emphasized in the development of SB products to increase utilization of the berry as a common meal component and to obtain value-added products to support human health.</p

Response of lignin and flavonoid metabolic pathways in Capsicum annuum to drought and waterlogging stresses

Water stress is a critical factor limiting the growth and development of Capsicum annuum. Flavonoids and lignin are important secondary metabolites that serve as signaling molecules in plant stress responses. However, the effects and regulatory mechanisms of lignin and flavonoids under water stress in Capsicum annuum remain unknown. The present study focused on the effects of drought and waterlogging stress on the morphology, hydrogen peroxide, and relative chlorophyll (SPAD), as well as enzyme activities, metabolite contents, and gene expression related to lignin and flavonoid metabolic pathways in Capsicum annuum. The results showed that drought and waterlogging stresses on the Capsicum annuum variety ‘Shuyu2’ significantly reduced plant height, stem thickness, and single-fruit weight, and increased fruit shape coefficients. Drought stress increased H2O2 and SPAD content, enhanced the activity levels of metabolic enzymes (phenylalanine deaminase, cinnamate 4-hydroxylase, coenzyme A ligase, peroxidase, and polyphenol oxidase), and up-regulated the expression of related genes, phenylalanine deaminase (PAL), trans-cinnamate monooxygenase (C4H), chalcone isomerase (CHI), and mangiferyl hydroxycinnamoyltransferase (HCT), while also promoting the accumulation of metabolites (total phenolics, flavonoids, and lignin) that have a restorative effect on drought stress. The continuous accumulation of H2O2 and the increase and then decrease in SPAD under waterlogging stress was also observed. Waterlogging stress also enhanced the activities of the above-mentioned metabolic enzymes, but the related genes were selectively down-regulated, e.g., C4H, 4CL, and peroxidase (POD), which resulted in the inhibition of the synthesis of lignin, flavonoids, and total phenols. These results indicate that the Capsicum annuum variety ‘Shuyu2’ is a drought-tolerant, waterlogging-sensitive variety. Meanwhile, the lignin and flavonoid pathway is a key pathway in response to drought stress in Capsicum annuum, which improves the theory of stress tolerance breeding in Capsicum annuum

Multiplexed detection of eight respiratory viruses based on nanozyme colorimetric microfluidic immunoassay

Pandemics caused by respiratory viruses, such as the SARS-CoV-1/2, influenza virus, and respiratory syncytial virus, have resulted in serious consequences to humans and a large number of deaths. The detection of such respiratory viruses in the early stages of infection can help control diseases by preventing the spread of viruses. However, the diversity of respiratory virus species and subtypes, their rapid antigenic mutations, and the limited viral release during the early stages of infection pose challenges to their detection. This work reports a multiplexed microfluidic immunoassay chip for simultaneous detection of eight respiratory viruses with noticeable infection population, namely, influenza A virus, influenza B virus, respiratory syncytial virus, SARS-CoV-2, human bocavirus, human metapneumovirus, adenovirus, and human parainfluenza viruses. The nanomaterial of the nanozyme (Au@Pt nanoparticles) was optimized to improve labeling efficiency and enhance the detection sensitivity significantly. Nanozyme-binding antibodies were used to detect viral proteins with a limit of detection of 0.1 pg/mL with the naked eye and a microplate reader within 40 min. Furthermore, specific antibodies were screened against the conserved proteins of each virus in the immunoassay, and the clinical sample detection showed high specificity without cross reactivity among the eight pathogens. In addition, the microfluidic chip immunoassay showed high accuracy, as compared with the RT-PCR assay for clinical sample detection, with 97.2%/94.3% positive/negative coincidence rates. This proposed approach thus provides a convenient, rapid, and sensitive method for simultaneous detection of eight respiratory viruses, which is meaningful for the early diagnosis of viral infections. Significantly, it can be widely used to detect pathogens and biomarkers by replacing only the antigen-specific antibodies

Phenolic compounds and antioxidant activities of tea-type infusions processed from sea buckthorn (Hippophaë rhamnoides) leaves

Sea buckthorn (Hippophaë rhamnoides, SB) leaves contain wide-ranging bioactive compounds. Processing of the leaves into beverages/food presents great potential for supporting human health. The research aimed to investigate the impact of different processing methods on phenolic compounds and antioxidant activities of tea type infusions prepared from SB leaves. Leaves of two SB cultivars, ‘Terhi’ and ‘Tytti’, were processed with different methods commonly used for tea processing. Phenolic compounds in the infusions were analyzed with High-Performance Liquid Chromatography-Diode-Array Detection and High-Performance Liquid Chromatography Electrospray Ionization-Tandem Mass Spectrometry. Isorhamnetin-3-O-glucoside-7-O-rhamnoside, isorhamnetin-3-O-rutinoside and kaempferol-3-O-hexoside-7-O-rhamnoside were the three major flavonol glycosides, stachyurin and casuarinin were the most abundant ellagitannins. The infusions of ‘Tytti’ contained more total phenolics than those of ‘Terhi’ (p </p