The purpose of the present study was to investigate the effect of a number of physical and chemical attributes upon muskmelon texture as described by sensory evaluation. Measurements of turgor pressure, percent moisture, total sugars, alcohol-insoluble-solids, three pectic fractions, total pectic materials, starch and cellulose were performed on 50 melons. The melons were purchased at random from a retail market in Corvallis, Oregon, over a five-week period during July and August, 1966. Subjective evaluation of textural quality was provided by a five-membered panel employing a pre-tested ballot. On five-point scales, judges rated resistance to cutting, resistance to biting, resistance to crushing, crispness, fibrousness and sweetness. Simple and multiple correlation analyses were performed to elucidate relationships between the objective and subjective observations. Considerable variation was found among melons for most of the attributes. Variation was largest in the case of water-soluble pectic substances and cellulose and least for alcohol-insoluble-solids. According to the results of this study, melon texture is determined to a great extent by the type and amount of cell wall constituents. Significant multiple correlations were found between cell wall constituents, cellulose and protopectin, and sensory panel scores for resistance to cutting, resistance to biting, resistance to crushing and crispness. Fruit maturity, as inferred from starch and protopectin content, also exerted an effect upon texture. Significant multiple correlations were found between starch and protopectin and panel scores for resistance to cutting, resistance to crushing and crispness. Although not specifically related to texture, a significant and positive simple correlation was found between total sugars and sweetness. Similarly, significant negative correlations were found between starch and total sugars and starch and sweetness. Turgor pressure, percent moisture, alcohol-insoluble-solids, total sugar, water-soluble pectic substances, pectates-pectinates and total pectic materials were found not to be reliable indicators of muskmelon texture. Although turgor pressure did not exhibit a significant relationship to any textural aspects, a trend was observed in the data. As a result of this observation and difficulty encountered in measuring turgor pressure, further work with this variable is recommended. Proximate composition of the melons analyzed compared favorably with published data. This observation lends confidence to the methods and analyses employed. Large standard deviations calculated for some of the attributes measured emphasize the extent of variation among melons, the difficulty in assessing texture in an objective manner and the problem encountered in marketing and purchasing the fresh fruit. / Graduation date: 1968

Large amounts of plant tissue are used in the production of many canned, frozen and dried foods. Some of this material is unsatisfactory in appearance and texture, despite careful processing from high quality raw materials. In the present study, the changes induced in soft fruits by controlled heating and freezing treatments were of prime concern. Strawberries and tomatoes were canned and frozen in 60° B sucrose syrup, stored for 3-6 months and examined by physical and chemical methods. Measurements of the texture, pectins, hemicelluloses, cellulose, nitrogen, ash and ash constituents, were made on raw, frozen and canned samples. The tissues were sliced, macerated with 0.4 percent sodium hexametaphosphate, and screened. The cell suspensions were dialysed and stored at 35°F, with toluene as a preservative. The cell suspensions were analyzed similarly to the tissue samples, and the reactivity of the cell suspensions with sugars and electrolytes was investigated. The results indicated the following conclusions: 1) No significant difference was found between the effects of canning and freezing on the texture of the fruits, as determined by the Shear Press, although major differences were found between the fresh and processed samples. 2) Drained weights were lower when the fruits were canned than when frozen, especially in the strawberries. 3) Histological changes brought about by the treatments were more marked in the frozen than in the canned fruits. Freezing caused severe breakage of cell walls, plus some cell separation, whereas canning tended to cause more shrinkage of cells without much breakage or separation. Adhesion between cells was increased in the heated packs. Damage to cells increased as cell size increased. The study showed that more emphasis should be placed on selecting varieties of fruits for processing which have a smaller mean cell size, and thicker cell walls. 4) Aqueous suspensions of parenchyma cells were found to be a useful means of studying the several mechanisms involved in textural and drained weight changes. 5) No sorption affinity was found between dialysed, depectinized parenchyma cells and sucrose or glucose. 6) Dialysed cells were negatively charged, highly hydrated, and formed viscous suspensions at low concentrations. 7) The addition of small amounts of cations, particularly H⁺ ion and Al⁺⁺⁺ ion, precipitated cell suspensions, by suppressing the ionization of the carboxyl group or by salt formation. 8) A new hypothesis was proposed which assigned an important role to the acids and other electrolytes of fruits, in governing the textural and drained weight characteristics of such products. It was proposed that the quantity of acids and other electrolytes which become distributed throughout the cell during processing, causes a reduction of cell hydration including a shrinkage of cell walls, which could be partially reversed during subsequent storage. / Graduation date: 1963

Graduation date: 1953

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

CNPq / O morangueiro é uma das culturas agrícolas que apresentam o maior custo de produção, principalmente devido a aquisição das mudas. Esse fato tem levado os produtores a manter as plantas por mais uma safra, devido ao baixo custo vinculado a essa prática. Contudo, pouco se sabe sobre o impacto dessa prática sobre a qualidade do fruto. O objetivo deste trabalho foi avaliar a qualidade de frutos de morangueiro de primeira (2013) e de segunda safra (2014) de um mesmo cultivo, levando em consideração aspectos físicos, químicos e nutricionais dos frutos. Posteriormente foi elaborado um queijo tipo Petit suisse com a cultivar Camarosa que apresentou os maiores teores de substâncias antioxidantes polares. Para as características físicas, o tamanho não difereriu em relação ás épocas de cultivo, mas os frutos de primeira época apresentaram-se mais vermelhos do que os de segunda época, o que pode estar relacionado com o teor de fenólicos totais. Com relação as características químicas (pH, sólidos solúveis e acidez titulável), observou-se que os frutos de primeira época apresentaram pH maior e menor teor de acidez titulável. Esses dados sugerem que sensorialmente o consumidor pode preferir os frutos de primeira época. A atividade antioxidante (ABTS) e o teor de antocianinas dos frutos de morango foi maior na segunda época de cultivo; e a atividade antioxidante (DPPH), compostos fenólicos e vitamina C apresentaram valores superiores na primeira época de cultivo. Esses resultados sugerem que dependendo da época de cultivo os frutos de morango possuem diferentes teores de substâncias bioativas em sua composição, que podem atuar na nutrição humana. Para a elaboração do queijo tipo Petit suisse, optou-se pela cultivar Camarosa, pois em ambas as épocas de cultivo essa cultivar apresentou maior teor de antioxidantes polares (vitamina C, compostos fenólicos, antocianinas e flavonoides) do que as demais cultivares. Ao elaborar o queijo tipo Petit Suisse observou-se que com a adição do microencapsulado de polpa de goiaba o teor de carotenoides totais do produto aumentou, e com a adição da farinha de feijão houve aumento no valor proteíco e mudança na textura do queijo. Ambos os ingredientes interferiram no pH do produto. Com os resultados obtidos pode-se afirmar que os ingredientes microencapsulado de polpa de goiaba e farinha de feijão agregaram valor nutricional ao queijo tipo Petit Suisse, devido ao maior teor de proteínas e carotenoides totais, indicando que esses ingredientes podem ser utilizados para a fabricação de outros produtos alimentícios. / Strawberry is one of the crops that have the highest cost of production, mainly due to the acquisition of the seedlings. This has led producers to keep the plants for another season, due to low cost linked to this practice. However, little is known about the impact of this practice on the quality of the fruit. The objective of this study was to evaluate the quality of the first fruits of strawberry (2013) and second crop (2014) of the same crop, taking into account physical, chemical and nutritional fruit. Later we designed a cheese type Petit Suisse with the cultivar Camarosa showed the highest levels of polar antioxidants. For physical characteristics, size does not difereriu compared ace growing seasons, but the fruits of the first season were more red than the second season, which may be related to the total phenolic content. Regarding the chemical characteristics (pH, soluble solids and titratable acidity), it was observed that the fruit first period had lower pH and higher titratable acidity. These data suggest that sensory consumers may prefer the fruits of the first season. The antioxidant activity (ABTS) and the anthocyanin content of strawberry fruits was higher in the second growing season; and the antioxidant activity (DPPH), phenolic compounds and vitamin C had higher values in the first growing season. These results suggest that depending on the growing season the strawberry fruits have different levels of bioactive substances in its composition, which can act in human nutrition. In preparing the cheese type Petit suisse, we chose to cultivate Camarosa because in both growing seasons this cultivar showed higher content of polar antioxidants (vitamin C, phenolic compounds, anthocyanins and flavonoids) than the other cultivars. In preparing the cheese type Petit Suisse was observed that with the addition of guava pulp microencapsulated the total carotenoid content of the product increased, and with the addition of bean flour was increased-protein value and change in the texture of the cheese. Both ingredients interfere in the pH of the product. With the obtained results it can be stated that the ingredients microencapsulated of guava pulp and bean flour added nutritional value to cheese type Petit suisse, due to the high amount of protein and carotenoids, indicating that these ingredients can be used to manufacture other food products. / 5000

M.Sc. / Please refer to full text to view abstract

No description available.

The influence of rootstock and canopy density on grape berry composition was investigated over the summer of 2003-2004 on a commercial vineyard at Waipara, North Canterbury. This experiment was designed to investigate the influence of rootstock and canopy density on the acid composition, potassium (K) content and final pH of harvested fruit (Pinot Noir AM 10/5 Lincoln Selection). The trial block consisted of eight rootstocks laid out to an 8 x 8 latin square, each plot consisting of five vines of the same rootstock. Two canopy treatments were overlaid the block (down whole rows, assigned randomly, four rows to each treatment); one treatment allowed to grow naturally, in the other treatment the canopy was thinned removing double burst shoots and laterals. The bunch numbers were adjusted in the Unthinned canopy treatment (UCT) to match the Thinned canopy treatment (TCT). Information was gathered to assess: the canopy size and density (Pinot Quadrat Leaf Layer and Percent Gaps and canopy porosity), the plant yield (and berry size, berries per cluster, cluster weight, clusters per plant), plant K levels at flowering and veraison (from petioles and leaf blades) and berry composition at harvest (soluble solids (as brix), K, titratable acidity (TA), tartaric acid concentration, malic acid concentration and pH). The trial area was non-irrigated on clay loam soils and viticultural management was to best commercial practice. It was found that although rootstock influenced the levels of K in the plant and in the juice at harvest, the level of K in the juice did not influence pH in this experiment (range of rootstock juice K: 808 ppm to 928 ppm, l.s.d. = 75 ppm). The level of tartaric acid concentration in the juice was found to be the dominant influence on the level of pH in this experiment (rootstock pH range: 3.21 to 3.39, l.s.d. = 0.05). The juice concentration of tartaric acid was influenced by both rootstock (rootstock range 4.0 to 4.7 g/L, l.s.d = 0.4) and canopy density (UCT = 4.1, TCT = 4.7, l.s.d. = 0.4), decreased shading positively increasing the level of tartaric acid. The malic acid concentration in the juice was positively influenced by increasing canopy density (UCT = 4.7 g/L, TCT = 4.1 g/L, l.s.d = 0.4) and this played a minor role in the determination of pH in this experiment; an influence of rootstock on the level of malic acid concentration was found. The malic acid concentration strongly influenced the determination of TA (UCT = 11.0 g/L, TCT = 10.2 g/L, l.s.d = 0.5); tartaric acid concentration had a minor influence on the recorded TA. Attempts to characterise the influence of rootstock on malic acid, tartaric acid and pH were inconclusive. Rootstock was found to influence the canopy variables measured in this experiment and the recorded average plant yield. Crosses of Vitis rupestris were found to exhibit the most canopy vigour and those derived from Vitis berlandieri and Vitis riparia the least. The Canopy treatment did not show an influence over yield but the rootstock was found to influence plant yield, through the numbers of berries set in a cluster and the final harvest cluster weight. The influence of rootstock on pH may be described by the influence it exerts on canopy growth and yield but this was thought unlikely. Further research is required to describe the nature of the rootstock influence on K, malic acid, tartaric acid and pH.

Vineyards in the Mid-Atlantic often have large, vigorous vines that can be costly to manage and produce inadequate fruit for wine production. Dense canopies increase the incidence of fungal disease, require greater allocation of resources to manage, and inhibit fruit development. The primary objective of these studies was to determine effective vine-size modification treatments that would optimize fruit quality, while reducing labor and chemical control. Research factors included root manipulation, under-trellis ground cover, and rootstock. Treatment levels were root bag (RBG) or no root manipulation (NRM); under-trellis cover crop (CC) or herbicide strip (HERB); and one of three rootstocks: 101-14, Riparia Gloire, or 420-A. Effects of these treatments were measured in two experiments: Experiment I compared combinations of all three treatments, while Experiment II explored the individual effects of root restriction using root bags of varying volumes. Root restriction consistently demonstrated the ability to reduce vegetative growth and vine water status. In the first experiment fruit-zone photosynthetic photon flux density (PPFD) was increased by 234% in RBG vines. Timed canopy management tasks indicated that RBG canopies required about half the labor time of NRM canopies. Anthocyanin concentration and total phenolic content were increased by 20% and 19% respectively in RBG fruit. CC increased fruit-zone PPFD by 62%, and increased soluble solids and color compounds. The 420-A rootstock reduced potassium uptake, resulting in lower must potassium concentration. Results demonstrated that these treatments significantly reduce vegetative growth in a humid climate, decrease management labor, and produce higher quality fruit. / Master of Science

Reducing disease and increasing fruit quality in vigorous vineyards with dense canopies is demanding of time and resources; unfortunately, vineyards of this nature are common in humid environments. This study investigated the effectiveness with which vine capacity and water status could be regulated as well as if they related to fruit quality and wine sensory perception. The treatments regulating vine size and water status were under-trellis groundcover, root manipulation, rootstocks, and irrigation. Treatments were arranged in a strip-split-split plot design before the introduction of the irrigation treatment resulted in incomplete replication in each block. Treatment levels were under-trellis cover crop (CC) compared to under-trellis herbicide (Herb); root restriction bags (RBG) compared to no root manipulation (NRM); three compared rootstocks (101-14, 420-A, riparia Gloire); low water stress (LOW) compared to high water stress (HIGH). Vines grown with RBG and CC regulated vegetative growth more so than conventional treatments, resulting in 56% and 23% greater cluster exposure flux availability (CEFA). High water stress (HIGH) and RBG reduced stem water potential and discriminated less against 13C. Vines grown with RBG and CC consistently reduced harvest berry weight by 17 and 6% compared to conventional treatments. Estimated phenolics were consistently increased by RBG and were correlated with berry weight, vine capacity and CEFA. Sensory attributes were significantly distinguishable between wines produced from vines that differed in both vine capacity and water status, amongst other responses. Treatments have been identified that can alter the sensory perception of wines, with the potential to improve wine quality. / Master of Science