ALKALI-PROCESSED SWEETPOTATO FRENCH FRIES1

A combination of alkali (sodium phosphate or calcium chloride) infiltration and blanching and their order of application were studied for their effect on the sensory and physico-chemical (moisture, fat, sugars, and shear force) quality of sweetpotato French fries (SPFF) made from sweetpotatoes (SP) stored for 3 months or 1 year. Sensory quality (taste, texture, and overall acceptability) were evaluated using a nine-point hedonic scale. Treatment of SP strips with sodium phosphate solutions prior to blanching caused an increase in firmness as compared with untreated strips. For SPFF produced from SP stored 3 months, sensory quality of treated SPFF was indistinguishable from untreated SPFF. However, for SP processed at 1 year of storage, the sensory texture of treated samples was more acceptable than the sensory texture of untreated samples. Shear force data indicated that the firmest samples did not have the most acceptable sensory texture, indicating that there is an optimal level of shear force that gives the “right” amount of resistance to chewing to result in a more acceptable product. This process can be used in the manufacture SPFF from SP stored up to 1 year.     

Textural Properties and Sensory Quality of Processed Sweetpotatoes as Affected by Low Temperature Blanching

Sweetpotatoes (SP) stored for 9–12 mo after harvest were cut into cylindrical pieces and, following factorial experiments and response surface design, were blanched at 50–80°C for 15–274 min. Instrumental textural properties were measured by uniaxial compression and texture profile analysis. Samples of selected blanching treatments were canned in syrup for textural and sensory evaluations. Both blanching temperature and time had significant effects on firmness. Optimal temperature for maximal firmness retention was about 62°C. For canned SP, the 62°C blanched samples were more intact (2–3-fold) and firmer (2–7-fold) than controls. Sensory texture and overall acceptability were greatest for samples blanched at 62°C for 30 or 45 min before canning.     

The effect of the pre-treatments and the long and short-term frozen storage on the quality of raspberry (cv. Heritage)

Results are presented of the effect of pre-treatments before freezing followed by long and short-term frozen storage (12 months at –18 °C and 24 days suffering temperature fluctuations between –18 °C and –12 °C) on quality parameters of raspberry. Pre-treatments were carried out with calcium, low methoxyl pectin, a combined solution, and results compared with untreated control fruits. Kramer shear, back extrusion, compression, and multiple penetration tests were used to measure rheological behavior. One-hundred mM CaCl₂ reduced the long and short-term frozen storage induced loss of firmness. For long-term storage at –18 °C, a softening of the tissue became evident between 3 and 12 months and at each date test the stored fruits were firmer than those without storage. For short-term storage with fluctuations, the loss of firmness was evident between 0 and 24 days, and at all the testing dates the stored fruits were softer than those without storage. Results evidenced a higher cell damage in the short-term frozen storage. Coefficients of softening per day suffering fluctuation were determined, the highest values being given by Kramer shear energy and back extrusion maximum force (>1%). Short-term frozen storage affected physical and physico-chemical characteristics, increasing the saturation (r) and the anthocyanins and decreasing the ascorbic acid of the raspberries. In both storage conditions, pre-treatments reduced the drip loss, which correlated best with the Kramer shear energy. Panelists detected mainly time effect on the sensory firmness. For long-term, sensory firmness and juiciness gave the highest correlations with back extrusion maximum force, while for the short-term, sensory firmness and drip loss gave the highest correlations with the Kramer shear energy. SEM revealed different degrees of mechanical damage to structure, which accounted for rheological behavior of the fruits.     

Utilization of Cheese Whey Permeate in Canned Beans and Plums

Navy and kidney beans (Phaseolus vulgaris) were hydrated in water, then canned in brines designated as control, whey permeate (WP), and hydrolyzed lactose whey permeate (HP). Hunter Lab Color Difference and Kramer Shear texture analyses indicated general darkening and increased firmness in permeate treated beans. Total solids and ash increased significantly in the treated samples. There was a significantly lower preference for beans treated with permeate fractions than for control beans. Plums were canned in a control sucrose syrup (20° Brix) and in syrups with 5, 10, 15, 20, and 25% replacement of sucrose with HP, or crystalline glucose-galactose (GG) mixture. HP plums were generally darker in color and similar in texture to the control samples. Sensory tests showed that general acceptability of HP plums was similar to control samples.     

Sensory and Nutritional Quality of Split Peas (Pisum Sativum) Stored up to 34 Y in Residential Storage

ABSTRACT: The sensory and nutritional quality of split peas stored up to 34 y was determined. Nine samples of split peas representing 5 retail brands packaged in Nr 10 cans and stored at room temperature were obtained from donors. Duplicate cans of a fresh sample of split peas were purchased as controls. Can head space oxygen ranged from 0.255% to 20.1%. Water activity of the raw split peas ranged from 0.41 to 0.56. The green color of the raw split peas decreased over time as shown by increasing CIE a* values. Flavor, appearance, texture, and overall liking hedonic scores (9-point scale) of split-pea soup made from each sample ranged from 3.7 to 6.7 and decreased over time. Hedonic scores for appearance were correlated with the decrease in raw product green color (r²= 0.65). Hedonic scores for soup texture declined over time, which corresponded with increasing hardness of the cooked peas as measured by a TA.XT2 texture analyzer. All samples were judged to be acceptable in an emergency situation by over 75% of sensory panelists. Available thiamin was significantly lower in older samples while riboflavin remained unchanged. The results indicate that split pea quality declines over time, but the product maintains sufficient sensory acceptance to be considered for potential use in emergency storage and other applications where minimal stock rotation is a common practice.     

Preparation and Storage of 72° Brix Orange Juice Concentrate

Each year, thousands of tons of citrus concentrate are stored and transported throughout the world at 62° Brix. Increasing this concentration to 72° Brix can result in substantial savings. Fresh orange juice, treated mechanically or with pectic enzymes to reduce its viscosity, was concentrated to 72° Brix in a commercial processing plant, then samples were stored in barrels in a tank farm at ?7 or at 4°C. At monthly intervals, samples were blended to make 41.8° Brix Frozen Concentrated Orange Juice. The enzyme-treated samples had lower viscosity than those mechanically treated. Vitamin C retention levels were > 94% after 6 months storage at 4°C. Taste evaluations rated the product ‘very good’ and furfural levels were well below that which indicates off flavors. Browning tended to increase with storage time and temperature.     

Effect of natural antioxidants and vacuum packaging on the quality of buffalo meat nuggets during refrigerated storage

Buffalo meat nuggets (BMN) were incorporated with 500 ppm sodium ascorbate, 10 ppm -tocopherol acetate and 0.5% sodium tripolyphosphate while processing. There were three experimental groups of BMN, namely control aerobic packaged (CAP), treated aerobic packaged (TAP) and treated vacuum packaged (TVP), refrigerated and stored at 4 °C. It was observed that the treated samples (TAP and TVP) had significantly (p < 0.05) higher pH, W-B shear force, moisture and protein contents, sensory attributes and lower free fatty acids content in comparison to CAP samples. Vacuum packed nuggets (TVP) had significantly (p < 0.05) lower free fatty acid content, higher lactobacilli and total anaerobe counts and markedly higher scores for flavour and overall palatability, even at the 25th day of storage. Product quality reduced as storage time increased. Use of natural antioxidants and vacuum packaging extended the shelf life of BMN from 10 to 30 days under refrigerated storage.     

Comparison of the texture of fresh and preserved Agaricus bisporus and Boletus edulis mushrooms

This work compares changes during the production process and storage period in the texture of canned Agaricus bisporus and Boletus edulis mushrooms previously blanched in water, blanched or soaked and blanched in solutions containing citric, l ‐ascorbic and lactic acids. The texture was examined using instruments [textural profile analysis (TPA), Kramer shear cell (KSC)] and sensory analysis [five‐point, profiling (P)]. Canning B. edulis mushrooms reduced their hardness, chewiness and gumminess (TPA), the values for force and work (KC), and brittleness and crispiness (P), although increasing their cohesiveness (TPA). Canning A. bisporus mushrooms reduced their hardness (TPA) and the expenditure of work, but increased their cohesiveness, hardness, crispiness and firmness (P). Twelve‐month storage of both species of canned mushrooms led to a reduction in brittleness and crispiness (P). The type of pre‐treatment applied affected the texture only when determined using profile analysis, and significant differences in hardness, crispiness and firmness between blanched‐only and soaked and blanched products were mainly found in B. edulis.     

RELATIONSHIP BETWEEN THE PHYSICAL PROPERTIES OF DRIED BEANS AND THEIR TEXTURAL CHARACTERISTICS AFTER PROCESSING

Baked beans in brine and in tomato sauce were prepared using samples from six different uarieties of bean. The dry unprocessed-beans were tested by means of compression and puncture, shearing, back extrusion and compression tests, as well as to sensory evaluation of texture .
For canned beans in brine, the maximum forces for compression and back extrusion were found to be linearly dependent on the maximum force for compression of the dry beans. In the case of beans canned in tomato sauce, only the maximum force for back extrusion exhibited linear dependence. When tomato sauce was used, some softening was observed. The maximum force for back extrusion was correlated to sensory firmness, and the energy for back extrusion to sensory chewiness .     

Quality and sensory characteristics of hard red wheat after residential storage for up to 32 y

Samples of hard red wheat packaged for long-term storage, ranging in age from 0 to 32 y, were obtained from donors in residential households. All samples had been stored under nonabusive conditions (7% to 10% moisture, 13 to 27 °C). Selected quality parameters of the wheat (moisture, thiamin, free fatty acids, flour extraction rate, bread loaf volume, and bread firmness) and sensory properties of bread made from the stored wheat (aroma, appearance, texture, flavor, overall liking, acceptance for use as part of the regular diet, and acceptance for use in emergency situations) were evaluated. Free fatty acids increased significantly from 0.897 to 11.8 μmol/g, and flour extraction rate decreased significantly from 76.5% to 69.9% over time. None of the other quality parameters measured (moisture, thiamin, bread loaf volume, and bread firmness) were significantly correlated with wheat storage time. Panelists who frequently or occasionally consume whole wheat bread rated all breads made from the stored wheat with hedonic scores (9-point scale) of at least 6.4 (like slightly to moderately). Consumer ratings of bread texture, flavor, and overall acceptability were negatively correlated with storage time (P < 0.001); however, at least 70% of panelists indicated that they would consume the bread as part of their regular diet even after 32 y of wheat storage, while over 97% would do so in an emergency. These data indicate that wheat maintains nutritional quality and makes acceptable bread when stored up to 32 y at 13 to 27 °C and 7% to 10% moisture. Practical Application: Wheat stored for the purposes of disaster relief has the potential of being stored for extremely long periods of time, which may result in undesirable changes in milling and baking quality. Therefore, we tested wheat that had been stored under residential conditions for up to 32 y to determine its functional quality and consumer acceptability. Our results indicate that wheat of low moisture (7% to 10%) packaged in sealed cans and stored for up to 32 y at or below typical room temperature retains quality and can be made into bread that is well accepted by consumers. Thus, whole wheat has good long-term storage stability and can be recommended for emergency food supplies.     

Effect of Thermal Process Time on Quality of "Shrimp Kuruma" in Retortable Pouches and Aluminum Cans

ABSTRACT:  The effect of processing time on biochemical, sensory characteristics, and instrumental texture profiles of "Shrimp Kuruma" in retortable pouches and aluminum cans with equal pack weight and lethality was studied. Processing in pouches resulted in a 35% reduction in processing time compared to cans for equal lethality ( F ₀ 8.0). Thermal processing resulted in a 14% loss of water in canned samples compared to 9% in pouched products. Thermal processing resulted in an increase in the volatile compounds and a decrease in the oxidation products in both canned and pouched samples. Products processed in pouches were rated as lighter in color, more succulent, and more desirable in firmness compared to products in cans. Chewiness and hardness showed a significant difference ( P < 0.05) between the 2 treatments.     

Textural and sensory characteristics of whole and skimmed flavored set-type yogurt during long storage

A study of refrigerated storage (10°C for 91 d) of whole and skimmed flavored set-type yogurt was made. Comparison with storage at 20°C for 21 d and 30°C for 3 d (accelerated) was also carried out. Refrigerated storage yogurts were assessed by a trained panel and by a consumer panel. Trained-panel scores were correlated to instrumental data, and the acceptability data for long storage were studied using consumer criteria. In all cases, after-storage pH values barely changed over storage time, indicating that the yogurt samples did not develop much acidity under any of the storage conditions studied. The profile of the instrumental texture curves obtained corresponded to a firm gel, which broke after a plunger penetrated the sample, and the firmness values of the whole yogurt were lower than for the skimmed yogurt under all the storage conditions studied. From a microbiological point of view, the viability of the yogurts was adequate at the different storage times and temperatures studied, although those stored at 10°C for long periods would not comply with some countries’ minimum requirements. Logistic regression of the data from a 50-consumer sensory evaluation showed that the probability of the whole yogurt being accepted after 91 d storage at 10°C was around 40%, whereas for the skimmed yogurt it was only 15%, largely because the skimmed yogurt developed certain negative attributes at an earlier stage of storage than the whole yogurt.     

Studies on the quality characteristics of canned grapefruit segments

Summary. Segments prepared from grapefruits (var. Marsh Seedless) soften rapidly in the course of maturation of the fruit as evident from shear press readings for freshly peeled and canned segments. Storage of the fresh fruit for up to 9 days decreases firmness of the fresh segments and the loss in firmness increases with progressing maturation. Time and temperature of pasteurization affect significantly the firmness of the segments as well as their 'tendency to break'. the storage of the canned product, for up to 1 year had little effect upon drained weight, whereas texture and colour of the canned grapefruit segments were affected significantly.     

SENSORY FIRMNESS SCALE BASED ON GELATIN GELS

A series of gelatin gels was produced and scaled to resemble the firmness of typical meat samples used in texture evaluation. The maximum force required to cut through the gel sample was determined with a Warner-Bratzler instrument and a TA. TX2 Model Texture Analyzer. Samples were scaled depending on the shear force required to force a blade through the material. An untrained sensory panel of 30 people, and a trained panel of 12, confirmed the sensory scale using a triangle test and unstructured scales. Untrained panelists were able to distinguish a difference between gels in three tenderness categories (P ≤ 0.001) in three consecutive tests. Trained panelists detected significant differences between scaled standards. Results suggest that scaled firmness standards based on gelatin gels provide a good model for meat tenderness sensory training.     

EXTENDED STORAGE LIFE OF LITCHI FRUIT USING CONTROLLED ATMOSPHERE AND LOW TEMPERATURE

The postharvest quality of litchi (Litchi chinensis Sonn.) cv. Bombay stored under controlled atmosphere (CA) at 3.5% O₂and 3.5% CO₂, 2C temperature and 92–95% relative humidity was studied. Fruits were also held in regular atmosphere (RA) maintained at 2C temperature and 92–95% relative humidity. Fruits kept at normal ambient conditions were used as controls. Various quality attributes measured revealed that fruits stored in CA exhibited Hunter “a” values of 11.2 after 56 days of storage, indicating the beneficial effect of CA on retaining the red color of litchi fruits. Fruits held in RA exhibited Hunter “a” values (7.9) lower than that of CA‐stored litchi, showing that browning of litchi was noticeable in RA. Loss of weight was lowest (4.9%) for the fruits stored in CA compared to those stored in RA (11.0%) and control (33.1%). Loss of acidity and ascorbic acid content of fruits stored in CA were less than that of RA. The smallest increase of litchi firmness and pericarp puncture strength of 2.2 and 3.9 times of initial level, respectively, were observed even after 56 days of storage in CA. Total soluble solid of litchi increased from 19.3° Brix at harvest to 23.0° Brix until 48 days of storage in CA after which it declined to 22.8 °Brix. The sensory evaluation of aril color and taste showed that the fruits held in CA were rated good throughout 56 days of storage.     

Aseptic processing of apricots in syrup by means of a continuous pilot scale ohmic unit

In the present study the effect of ohmic heating processing on the quality and shelf-life of apricots in syrup was investigated.Each 100 g of product contained 30 g of pre-heated syrup (15°Brix) and 70 g of blanched apricot pieces with a cubic shape (size 1.2 cm). The liquid-solid mixture (pH < 4) was pasteurized at 90 °C for about 113 s in a 30 kW aseptic continuous pilot ohmic system using a 25 kHz alternating electric current. The aseptically packaged samples were stored at 25 °C and periodically examined over one year period. The parameters measured during the preservation period were: pH, °Brix, color, ascorbic acid content, and microbial spoilage.During the shelf-life, no swelling of the packages was detected. Moreover, the product kept its microbiological stability during the whole storage period of 52 weeks. The ascorbic acid content was slightly reduced by the elctrothermal treatment. However, it was well preserved for the entire storage time. Similarly, the quality characteristics of the fresh apricots in syrup were not adversely affected by ohmic processing and a high retention of the quality attributes was observed during the storage time.     

Meat tenderization by calcium chloride after osmotic dehydration

In this study, meat was tenderized by dipping the meat in a calcium-containing solution after osmotic dehydration. Dehydrated meats were dipped in a 150 mM calcium chloride solution for 3 h, and after that stored for 24, 48, and 168 h at 3 ～ 4°C. Then, meat was subjected to texture measurement, sensory evaluations, biochemical analysis and histological observations. A gradual decrease in the firmness and higher tenderness sensory scores were observed in the meat treated with calcium chloride as compared with the untreated meat. Few differences were observed in water holding capacity by treatment at any stage of storage. A gradual increase in the myofibril fragmentation from the calcium chloride-treated meats was observed throughout the storage compared with the controls. Broadening of the I band and a disordered Z-line were observed in the treated meat. The deformation of the honeycomb-like structure of the endomysium was also observed in the treated samples. Therefore, the dipping in 150 mM calcium chloride solution after dehydration can be applied to improve meat tenderness without detrimental effects on other palatability and quality traits.     

IDENTIFICATION OF THE MAIN TEXTURAL CHARACTERISTICS OF CANNED PEACHES AND THE EFFECTS OF PROCESSING VARIABLES

The texture profile of canned peach fruits was studied using magnitude estimation as a scaling method. Their sensory characteristics were assessed using as a modulus either a model fruit or a real fruit sample. The sequence of appearance of the textural characteristics was determined during 4 stages of assessment (nonoral, first bite, during mastication, after effects). Four different varieties of peach fruits were canned and the effect of four processing variables (level of heat treatment, degree of ripeness, sugar concentration in the processing liquid and hardness of the processing liquid) on the texture profile of the fruits was examined. The results showed that an increase in the severity of the heat treatment and the degree of ripeness of the fruit resulted in a decrease in the firmness, crunchiness and chewiness of the canned fruit. Fibrousness was similarly affected but to a lesser extent. Freshness and juiciness were also negatively affected by these variables. An increase in the sugar concentration and hardness of the processing liquid resulted in an increase in the firmness, crunchiness and chewiness of the canned fruit. Fibrousness, freshness and juiciness were similarly affected but to a lesser extent.     

Microbial, physical-chemical and sensory spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method

The aim was to study spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method. Samples were packaged under vacuum into polyamide-polypropylene pouches, cooked at an oven temperature/time of 70 °C/12 h, chilled at 3 °C and stored at 2 °C for 0, 5 or 10 weeks. Microbial (psychrotrophs, lactic acid bacteria, Enterobacteriaceae, moulds and yeasts), physical–chemical (pH, water activity, TBARS, acidity, L^*a^*b^* colour, texture profile analysis and shear force) and sensory (appearance, odour, flavour, texture and acceptance) parameters were determined. The results showed that sensory spoilage preceded microbiological spoilage of sous vide pork loin. Counts bellow 1 log cfu/g of psychrotrophs, anaerobic psychrotrophs, Enterobacteriaceae and lactic acid bacteria were detected in any control week, while moderate counts (2–3 log cfu/g) of moulds and yeasts were found. Minor changes in water activity, lipid oxidation, CIELab colour, hardness, cohesiveness or gumminess were associated with spoilage of pork loin, only decreases of lactic acid, springiness and shear force were observed. The pork loin was unacceptable after 10 weeks. This loss of acceptance was mainly due to the deterioration of meaty flavour and odour, although the loss of appearance, juiciness and firmness also contributed. Moderate warmed-over and rancidity were detected. The sensory analysis was the most effective method for determining the shelf life of the sous vide pork-based dishes.