CHANGES IN RESIN COMPOSITION AND BREWING BEHAVIOUR OF HOPS DURING STORAGE

Changes in resin components and brewing value of several varieties of hops stored at two temperatures have been examined. Different varieties and temperatures of storage gave rise to significant changes in resin and oil composition, but these variables had little effect on bittering capacity.     

SEASONAL CHANGES IN PROXIMATE COMPOSITION OF ANCHOVY AND STORAGE STABILITY OF ANCHOVY OIL

Changes in proximate composition of anchovy were investigated during the catching season from October to March. In addition, stability of anchovy oil depending on storage temperature and time were studied. During the recent study, water, fat, protein and ash content of anchovy varied between 65.9–74.0%, 9.0–15.3%, 12.8–16.4% and 1.7–2.2%, respectively. The anchovy oil stored at 4C was found to be unacceptable for consumption at the end of the 90th day of storage according to peroxide, acid, unsaponifiable matter and thiobarbituric acid values. An identical sample stored at − 18C was acceptable for 120 days of storage, but eventually became unacceptable after that.

PRACTICAL APLICATIONS

Anchovy has a great economic importance for the Turkish fishery industry. Approximately 42% of the annual catch of anchovy is used in fish meal and oil production in Turkey ( SIS 2002 ). Therefore, the proximate composition of anchovy and seasonal changes have fundamental importance for consumers, manufacturers and wholesalers, because it is important for consumers to know what they eat, for manufacturers to figure out how they manage long storage stability for their products, and for wholesalers to buy equivalent of their payment. An important issue that has attracted attention of the manufacturers is the storage life of fish oil. Therefore, the results presented in this study are expected to be useful for the fish oil industry in Turkey or even in other countries processing anchovy into fish oil.     

CHANGES IN QUALITY OF DEHYDRATED KIBBLED ONIONS DURING STORAGE

SUMMARY— Dehydrated kibbled onions. of the Egyptian variety, containing 4-5% moisture, were stored under different conditions and their keeping quality as influenced by storage variables determined. 3 packaging materials, namely cans, polyethylene and Saran pouches were used. Samples were stored at temperatures of 15, 25 and 35°C at 44% relative humidity for 39 wk. Temperature of storage was found to have the largest effect on product quality. The can package was found to be superior to the flexible pouches; however, Saran pouches could be used under certain conditions. Moisture content increased significantly in polyethylene pouches at all temperatures, but in Saran pouches only at 25° C Absorbance of onion extracts, as measure of browning, increased significantly with storage temperature and to a smaller extent due to packaging materials. Products in polyethylene deteriorated most, while the difference between Saran- and can-packed products was small. A similar trend in results was found in tristimulus color determinations. All products stored at 15° C and those in cans at 25°C were found to be of good organoleptic quality. The pyruvic acid development potential could not be used as a sensitive indicator for determination of product quality.     

EVALUATION OF TIME-TEMPERATURE RELATED QUALITY CHANGES IN ICE CREAM DURING STORAGE

The keeping quality of vanilla-flavored ice cream was investigated during 21 weeks of storage. Ice cream samples at 4 different temperature treatments were evaluated for 3 attributes by 14 judges using a deviation-from-reference scale. Sampling tools and presentation containers were designed to provide uniform samples and serving temperatures without melting. The ice cream kept at a variable storage treatment showed a trend toward becoming less firm and darker in yellow than the other samples from the 86th day of storage onward. Differences in creaminess, hardness, and vanilla flavor were noticed in ice cream after 170 days of storage. A commercial time-temperature indicator was used to monitor temperature exposure; but, since indicator response was slower than published, no correlations could be made with quality changes.     

FROZEN STORAGE QUALITY CHANGES IN WHOLE JONAH CRABS

The Jonah crab is an underutilized species in the mid-Atlantic region, and use of the whole, frozen crab would broaden marketing options for this seafood product. We monitored quality changes in whole cooked crabs held in a blast freezer for up to 50 weeks. A sensory evaluation panel determined the point at which detectable differences appeared in the product. Microbiological testing was conducted at selected intervals to assess bacterial content. In a triangle test, frozen experimental samples of leg meat were first differentiated from frozen controls at approximately 24 weeks. No significant difference was defected in body meat for up to 33 weeks’ storage. Microbial quality was acceptable throughout the experiment.     

FLAVOR AND QUALITY CHANGES IN SWEET ONIONS DURING STORAGE AT ROOM TEMPERATURE

Flavor and quality parameters of onions (Allium cepa ‘Walla Walla Sweet’) were monitored for up to 7 weeks following harvest. Shelf-life of bulbs harvested earlier in the season was shorter than that of onions harvested 3 weeks later. Soluble solids of inner scales and average pyruvate, 3,4-dimethyl thiophene and disulfides content increased during the 4 week shelf-life at 22C of the onions harvested in June. These increases resulted in the final contents to be comparable to those of onions harvested on July 2, 1992, which were relatively stable. The pyruvate concentration was comparable to that of a mild, nonpungent onion. Correlations between pyruvate, thiophene and soluble solids were not significant. The relationship between 3,4-dimethyl thiophene, disulfides and onion flavor is discussed.     

CHANGES IN QUALITY ATTRIBUTES DURING STORAGE OF TOGWA, A LACTIC ACID FERMENTED GRUEL

Microbiological, physicochemical and sensory quality changes in togwa during storage at ambient tropical temperatures were monitored in unpasteurized and pasteurized samples with added sodium benzoate, potassium sorbate, propionic acid or a combination of sodium benzoate and potassium sorbate. The untreated samples were unacceptable within 48 h after production. Organic acids, volatile flavor compounds and fermentable sugars were monitored in untreated samples for up to 96 h. Ethanol, 2-methyl-1-propanol, 2-methyl-1-propanal, 3-methyl-1-butanol, 3-methyl-1-butanal, acetone, acetoin, lactic, succinic and formic acid increased significantly within 48 h. Pyroglutamic and pyruvic acid decreased and then increased, while uric acid and sugars decreased within 96 h. Sodium benzoate, potassium sorbate or their combination extended the shelf-life of the control samples by four days. Pasteurization at 97C/10 min reduced the total mesophilic bacteria, lactic acid bacteria, yeasts and Enterobacteriaceae counts to nil and maintained the pH, titratable acidity, specific gravity, and total soluble content constant, and the products were mildly acceptable during storage for up to 60 days. Pasteurization alone was comparable to the combined effects of pasteurization and treatment with preservatives on the quality of the product. Pasteurization alone may therefore be appropriate for small-scale production and increased commercialization.     

QUALITY OF COFFEE CREAMERS AS A FUNCTION OF PROTEIN SOURCE

Many U.S. consumers add a sweetener or creaming agent to their brewed coffee. An ideal creamer, when added to coffee, should remain stable, dissolve readily, and provide whitening ability. In general, these properties are imparted by the protein component. Four different proteins – sodium caseinate, isolated wheat protein, soy protein isolate and whey protein concentrate – were used to formulate coffee creamers, individually and in combination, and the resultant creamers were evaluated for functionality. Coffee creamers containing plant proteins had significantly greater apparent viscosity but lower L* values than did creamers made with dairy proteins. Creamers made with higher concentrations of isolated wheat protein exhibited syneresis, whereas no syneresis occurred if sodium caseinate was the predominant protein. Only the creamer formulated with soy protein isolate alone exhibited feathering when added to hot, brewed coffee. These results indicate that coffee creamers can be formulated with plant proteins and sodium caseinate.     

"DELICIOUS PILAFA" APPLE DENSITY CHANGES AS A QUALITY INDEX OF MASS LOSS DEGRADATION DURING STORAGE

ABSTRACT

Since many years, the mass density of many agricultural products has been used as a quality‐sorting criterion, and automatic machines have been developed for that purpose. According to the literature, apple flesh density seems to be related to flesh stiffness, but this behavior is not common among all cultivars. However, there is a lack of information on the evolution of apple density during storage. This study aims to investigate changes of “Delicious Pilafa” apple density during storage. Fruits have been preserved at 0, 10 and 16C. Experiments have been repeated for three successive storage periods. Linear equations between density and mass loss have been developed for two ranges of storage temperatures, 0–10C and 10–16C. Moreover, an efficient multifactor linear equation that relates density to storage time and mass loss has also been calculated. “Delicious Pilafa” apples are characterized by a high mass loss rate during storage. Thus, the relationships developed in this study could be useful for quality assessment of stored fruits according to their mass loss.

PRACTICAL APPLICATIONS

Mass loss of “Delicious pilafa” apple during storage can be estimated via fruit density and storage time using the developed equations that refers to a variety of storage conditions. Fruit density can be easily measured as well as storage time can be accurately estimated at a certain moment of storage. Such mass loss correlation is important for “Delicious pilafa” apples, characterized from high mass loss rates during storage and thus this prediction procedure could be very useful as an objective quality criterion during storage. Equations that relate mass loss and storage time with fruit density could be also useful for the estimation of fruit's volume. This is particularly important for respiration rate measurements, where fruits volume is required. Using such relations the estimation of volume is feasible only with weighting and without immersing fruits in water that could affect respiration activity and favor spoilage development.