EFFECT OF STORAGE ON THE SAFETY AND QUALITY OF FUFU FLOUR

Studies were carried out on the physicochemical characteristics and the fungi involved in the spoilage of fufu flour under storage at different relative humidities in ambient temperature.The physicochemical characteristics showed an increase in moisture content, decrease in swelling power, water‐binding capacity and pH throughout the storage period. Fungi growths were noticed on the samples at different times. Relative humidity of 33% and 76% for 56 days and 48 days, respectively, had the minimum number of growth when compared to others. The fungi that were isolated from the fufu were Aspergillus niger, Rhizopus spp., Geotrichum candida and Candida spp. This study therefore showed that fufu flour will keep best when it is stored under the condition of 33% relative humidity at room temperature.     

QUALITY OF SWEETPOTATO FLOUR DURING PROCESSING AND STORAGE

Sweetpotato flour can easily be promoted as a substitute for wheat flour in sweet baked products and can also be used for its high carotenoid content. However, the price of the sweetpotato flour must be competitive with wheat flour and be of good quality. This article defines and describes the different quality characteristics of sweetpotato flour. After an overview of the different steps and equipment used in the small-scale processing of sweetpotato flour, the influence of the different processing steps and storage on the quality characteristics are reviewed.     

添加马铃薯全粉对面包品质的影响

在面包制作时添加不同浓度的马铃薯全粉,通过测定面包的比容,对面包的品质进行综合评分,研究了马铃薯全粉对面包品质的影响.实验结果表明,适量添加马铃薯全粉能改善面包品质,最佳添加量为15%.     

酶制剂对国产面粉烘培品质的影响

主要研究4种酶制剂对国产面粉烘焙品质的影响.研究结果:国产面粉通过添加酶,使其烘焙品质有了明显改善,制作的面包比容、弹性、黏聚性增加;硬度和咀嚼度降低,经改良的国产面粉能制作出高品质面包.     

不同制粉工艺对面粉粉质特性和糊化特性的影响

脱皮制粉工艺先除去小麦部分皮层,再入磨,使后序的皮磨以及清粉系统大大简化.本试验利用两种工艺加工面粉后,用RVA测定和分析了面粉粉质特性和糊化特性的变化.结果表明,脱皮工艺下面粉的损伤淀粉含量减少、淀粉平均粒度变大、α-淀粉酶含量减少;降落数值和平均粒度分布分别与低谷粘度呈显著正相关（r=0.581,p＜0.05;r=0.603,p＜0.05）,衰减度和平均粒度呈显著的负相关（r=0.605,p＜0.05）;制粉工艺对中筋的南阳白麦和高筋的8901二等粉的影响最为显著,脱皮工艺下这两种面粉的峰值粘度和最终粘度明显增加,并且其衰减度较大;脱皮工艺的低谷粘度均高于传统工艺的同等面粉,但回生值较低.     

EFFECT OF MODIFIED ATMOSPHERE PACKAGING ON THE QUALITY OF SMOKED CATFISH

Smoked catfish were inoculated with Listeria ivanovii then packaged under 80% CO₂/20% N₂ (M₁) and 40% CO₂/30%O₂/130% N₂ (M₂) and stored at 2 and 8C. Noninoculated samples packaged under air (A) served as controls. Fillets stored under M₂ at 8C showed the fastest growth of L. ivanovii. L. ivanovii counts in samples stored under M₁ at both temperatures decreased significantly over time. Listeria growth was observed in samples stored under air at 2 and 8C after 2 weeks. APC results were similar to that of Listeria The highest TBA values were observed in M₂-stored samples followed by air-stored samples. Lightness ("L" values) increased significantly, whereas "a" (redgreen) and "b" (blue/yellow) values decreased in all atmospheres at both temperatures over time. The combined use of M₁ and 2C improved the quality of smoked catfish by inhibiting microbial growth and minimizing the extent of lipid oxidation.     

EFFECT OF COOLING DELAY AT HARVEST ON BROCCOLI QUALITY DURING POSTHARVEST STORAGE

Broccoli (cv ‘Green Duke’) was grown, harvested and cooled prior to simulated handling and storage. Delays of cooling were 0.5 and 3.0 h in one experiment and 0.5, 1 and 2 h in a subsequent experiment. Significant losses in market life of fresh broccoli were noted within the 3 h cooling delay period. Floret opening was the limiting visual quality characteristic in most treatments. Turgor was more limiting than color in all observed treatments. Using a systems approach a vertically-integrated broccoli handler could project the effects of cooling delays on shelf-life expectations within the prescribed handling system.     

EFFECT OF PACKAGING MATERIALS ON COLOR,VITAMIN C AND SENSORY QUALITY OF REFRIGERATED MANDARIN JUICE

ABSTRACT

Refrigerated mandarin juice was packed in four different containers, three cartons with different composition and one polyethylene terephthalate transparent bottle, and was stored at 4C for 90 days. During the storage of these juices, changes in the headspace gas composition, vitamin C, and CIE L*, a* and b* color coordinates were evaluated. In addition, a consumer panel evaluated the sensory color, fresh mandarin flavor and presence of off‐flavors in the juices. Experimental data indicated that the deterioration of mandarin juices (ascorbic acid degradation and darkening of color) was triggered by the rise in oxygen in the headspace of the storage containers. The type of container played a predominant role in determining the juice quality, with carton containers with an inner layer of aluminum foil providing the juices with the best quality throughout their storage.

PRACTICAL APPLICATIONS

Results from this study will provide manufacturers of mandarin juice with information dealing with the storage and quality of juices packed in different containers. In this way, if manufacturers want to use transparent polyethylene terephthalate (PET) bottles showing the color and appearance of the juice, they will be aware that the shelf life of the juice will be much shorter than in packed cartons; this reduction will be from more than 90 to 36 days (PET bottle). On the other hand, if manufacturers want to use carton for their packaging, they will be aware that using a container with a thick inner layer of aluminum foil will maintain the quality of the juice for a longer time (over 90 days) compared with a shelf life of about 54 days from cartons with an inner layer of ethylene vinyl alcohol copolymers.     

采收期对金红苹果贮藏品质的影响

以金红苹果为试材,研究不同采收期对金红苹果贮藏品质的影响,为金红苹果贮藏保鲜提供理论和实践依据.研究结果表明:在吉林地区,金红苹果适宜的采收期为8月末9月初.此期,果实的硬度约为11.00kg/cm2,可溶性固形物含量约为12.40%,可滴定酸含量约为0.76%.果实冷藏100d后,仍能保持硬度达7.90 kg/cm2,可溶性固形物含量约为11.30%,可滴定酸含量达0.50%,失重率4.70%,而且果实外观新鲜,腐烂率仅为0.50%.     

EFFECT OF PHYSIOLOGICAL MATURITY AT HARVEST ON PEACH QUALITY DURING LOW TEMPERATURE STORAGE

Peaches (cvs ‘Loring’ and ‘Redglobe’) were collected from five packinghouses within a 20 km radius on a single harvest date. Using color chips to categorize harvest maturity, fruit color and firmness were evaluated on the day of harvest. After 7 day storage at 5°C, designed to simulate maintenance of a cold-chain during wholesale distribution, peach color, firmness and sensory quality were determined. Color and flavor development were inhibited at 5° C but the softening rate increased at increasing levels of maturity. Separation of softening from flavor and color development has implications in study of ripening physiology of the peach and in assessing current handling practices.     

EFFECT OF STEAMED WHEAT FLOUR ON THE SENSORY QUALITY OF BATTER COATED PRODUCTS

Steaming of the wheat flour was done to improve the rheological as well as textural characteristics of batters used in coated products. The gluten forming protein completely denatured with increase in the steaming period. The apparent viscosity of the wheat flour batters increased with increasing solid concentration and steaming. A batter concentration of 33% of blend of native and steamed wheat flour used in the preparation of chiklunde (a traditional Indian batter coated snack made up of sweet filling and a wheat flour batter casing) scored 10.12 cm (on a scale of 15 cm) for sensory overall quality. The correlation between sensory attributes, composition of the casing and texture (peak force during shearing) showed that moisture was significantly positively related to adhesion (r = 0.70, p <0.05) and negatively related to crispness of the product (r=-0.74, p<0.05). The correlation obtained between fat content and crispness (r=0.89, p<0.01) indicated that increasing lat content increased the crispness of the product.     

EFFECT OF STORAGE TIME ON THE MALTING QUALITY OF SOME BARLEY VARIETIES

Changes in the malting quality of some barley varieties were monitored at monthly intervals from harvest All the varieties were found to improve after storage for up to one year. Varieties with poorer malting grades improved at a faster rate than good varieties, although ranking consistent with malting grade was maintained.     

EFFECT OF STORAGE CONDITIONS ON THE SENSORY QUALITY OF GROUND ARABICA COFFEE

The objective of this study was to determine how long ground coffee beans could be stored at room and freezing temperatures before sensory changes could be detected, and to identify specific attribute changes associated with this storage. Ground beans were stored for 0 (fresh), 1, 2 and 3 weeks at room and freezing temperatures. Coffee was prepared from each of these treatments and difference testing was performed. Paired comparison tests were conducted on the fresh, 1‐ and 2‐week‐stored coffee grounds to examine the attributes of coffee aroma, flavor, bitterness and overall preference. At room temperature storage, results indicated significant (P < 0.05) differences in the coffee prepared from fresh versus the 2‐week‐stored ground beans. Coffee made from freshly ground beans had a stronger coffee aroma, less bitterness and was more preferred compared with the beans stored for 1 or 2 weeks (P < 0.05). At freezer storage, differences were detected between coffee prepared from coffee grounds stored for 1 or 2 weeks. Coffee prepared from grounds stored for 2 weeks had a stronger coffee aroma and was more bitter compared with the other storage times (P < 0.05).     

THE EFFECT OF EXTRUDED FLOUR AND FERMENTATION TIME ON SOME QUALITY PARAMETERS OF IDLI

The effects on idli characteristics of fermentation time and substituting rice with differing proportions of rice flour extrusion‐cooked under different conditions were studied. The specific gravity, pH and viscosity of batter and idli characteristics such as expansion, compression force and sensory attributes were measured and described using regression to fit a response surface analysis. Fermentation time showed the most pronounced effect on specific gravity, pH and aqueous dispersion viscosity of batter and taste scores of idli. Substituting rice flour with extruded rice flour at different levels were observed to have significant effect on expansion and appearance scores of idlis. The textural scores and compression force was significantly affected by extrusion temperature. The formulation containing rice substituted by 30% extruded rice flour extruded at 175C and fermented for 24 h produced idlis with highest expansion and overall acceptability.