Frying Oil Temperature: Impact on Physical and Structural Properties of French Fries During the Par and Finish Frying Processes

The physical, mechanical, and structural changes in French fries at different frying temperatures (170, 180, and 190 °C) during par and finish frying were investigated. The experimental frying process includes blanching, par frying, freezing, and finish frying at the point of consumption. Par frying temperature had a greater effect on moisture reduction than on processing time with the greatest moisture loss at 180 °C after 160 s. At 180 °C, fries had the highest total oil uptake (29.56 % wb). Frying caused a significant change in color with the greatest effect at 190 °C. Micro-CT scan images showed structural changes in French fries over the course of the frying process. Frying time increased the volume of the pores relative to the size of the crust, and this was positively correlated with the hardness and shear cutting force. Overall, within the range of frying conditions studied, the higher temperature (190 °C) resulted in the lowest amount of oil uptake and the crispiest texture.     

Instrumental and Sensory Evaluation of Textural Properties of Extrudates from Blends of High Starch/High Protein Fractions of Dry Beans

A Wenger X5 single-screw extruder was used to produce bean extrudates from formulations modified by addition of high protein bean fraction or hull. The effect of process temperature was investigated. The higher the process temperature, the lower was the sample stress and the higher the sensory score for crispness. Product processed below 121°C was unacceptable. Crispness was good for samples containing 13–16% protein or 17–21% fiber; outside these ranges the extrudates were too hard. Shear stress increased uniformly with increasing protein or fiber content. A satisfactory correlation was observed between sensory and instrumental test results for texture: the higher the shearing stress, the lower was the sensory score for crispness.     

Potato Cubes Response to Water Blanching and High Hydrostatic Pressure

High hydrostatic pressure treatment (400 MPa, 15 min, 5–50°C) of potato cubes (2 × 2 × 2 cm) was compared with hot water blanching (100°C, 30–180 set). Inactivation of microorganisms and polyphenoloxidase, texture and density change, leaching of potassium and loss of ascorbic acid were monitored. Reduction of microbial counts was comparable for both methods and polyphenoloxidase was completely inactivated at 20°C, when dilute citric acid solutions (0.5 or 1.0%) were used as “immersion” medium. Hot water blanching and high pressure treatment resulted in samples of similar softness. Leaching of potassium was reduced 20% after pressure treatment on vacuum-packaged samples. Retention of ascorbic acid in pressure-treated samples was temperature dependent ranging from = 90% at 5°C to = 35% at 50°C.     

Subcritical water extraction of phenolic compounds from flaxseed meal sticks using accelerated solvent extractor (ASE)

Subcritical water extraction (SWE) is a technique based on the use of water as an extractant, at temperatures between 100 and 374 °C and at a pressure high enough to maintain the liquid state. SWE provides higher selectivities, low cost, and shorter extraction times. In this study, phenolic compounds in flaxseed (Linum usitatissimum L.) meal sticks were extracted with subcritical water using accelerated solvent extractor. For this aim, the interactions between temperature (160, 170, and 180 °C) and extraction time (5, 15, 30, and 60 min) for subcritical water extraction of SDG lignan, total phenolics, and total flavonoids from flaxseed meal sticks were investigated. The highest extraction yield of SDG lignan (77.01 %) in subcritical water extracts was determined at 160 °C for 60 min. However, high extraction yields were obtained as 70.67 and 72.57 % at 170 and 180 °C for 15 min, respectively. Also, the highest extraction yield of total phenolics (70.82 %) and total flavonoids (267.14 %) were determined at 180 °C for 15 min. Besides, high correlations between SDG lignan–total phenolics, SDG lignan–total flavonoids, and total phenolics–total flavonoids were obtained from 0.86 to 1 in water extracts.     

Quality Assurance of Model Infant Milk Formula Using a Front-Face Fluorescence Process Analytical Tool

Front-face fluorescence spectroscopy (FFFS) was evaluated as a quality assurance process analytical technology (PAT) tool for infant milk formula (IMF) manufacture. Batches of first-stage IMF (60:40 whey protein:casein ratio) powder were produced with protein:fat:lactose ratios of 1.3:3.6:7.3, differing only in heat treatment applied prior to spray drying (72, 95, or 115 °C for 15 s). Each IMF powder was stored at 15?±?2 °C and 37?±?2 °C and analyzed at months 0, 3, 6, and 12. Partial least squares (PLS) models were developed for IMF in both powder and liquid states using FFFS spectra to predict pre-drying heat treatment temperature, soluble protein content, and storage time. Models developed using tryptophan emission spectra for IMF powder predicted storage time, pre-drying heat treatment temperature, and soluble protein content with RMSECV values of 0.3 months, 8.3 °C, and 1.01 g protein/100 g powder, respectively. IMF powders were rehydrated to 13% total solids and analyzed using the vitamin A emission spectra. Models developed for rehydrated IMF predicted storage time and pre-drying heat treatment temperature with RMSECV values of 1.5 months and 6.7 °C, respectively. Surface free fats were predicted with an RMSECV range of 0.12–0.20% (w/w of powder) in rehydrated IMF. PLS discriminant analysis models developed for both powder and liquid IMF samples successfully discriminated for storage temperature. This preliminary study demonstrates the strong potential of FFFS as a PAT tool for IMF quality assurance.     

Effect of exogenous fludioxonil postharvest treatment on physiological response,physico-chemical,textural, phytochemical and sensory characteristics of pomegranate fruit

The study investigated the effects of fludioxonil (FLU) on the postharvest quality of pomegranate fruit (cv. Wonderful). Fruits were dipped in FLU concentrations (control, 150, 300 and 600 mg/L) and stored for 4 months at 5?°C and 90–95% relative humidity (RH) plus an additional 4 days at 20?°C and 65% RH. Effects of FLU were evaluated on physiological responses, quality and sensory attributes. Results showed that fruit weight loss and decay incidence were reduced by FLU treatment, with fruit treated with 600 mg/L concentration showing the best results. Fruit respiration rate was more influenced by storage duration than FLU concentration. The severity and occurrence of physiological disorders increased with storage duration but were more pronounced in fruits treated with FLU. Storage duration influenced fruit colour whereas aril colour was affected by FLU concentration. Untreated fruit showed better aril redness and chroma although treated fruit also had acceptable red colour. Chemical quality attributes of fruit juice were not significantly affected by FLU concentrations. Fruit treated with FLU had significantly (p?<?0.05) higher total phenolic content during storage although lower ascorbic acid content was observed compared to untreated fruit. Treating fruit with FLU resulted in better sensory attributes with regards to crispness, juiciness and sweetness. Overall, this study showed that fruit treated with FLU at 600 mg/L had the best quality with respect to decay incidence, weight loss, total phenolics and sensory attributes.     

Texture of Glassy Corn Cakes as a Function of Moisture Content

Glass transition temperatures of yellow and white corn cakes were investigated within the moisture range of 2 to 32% (w/w) using dynamic differential scanning calorimetry. All measurements were conducted at 10°C/min heating rate, 30 sec equilibrium period, and 1°C amplitude. Effects of water plasticization on corn cakes were predicted by the Gordon-Taylor's equation. Moisture sorption isotherms were established using BET and GAB equations. Relationships were found among glass transition temperature, moisture content and cake texture. The loss of crispness of corn cakes occurred within the glassy state. The initial loss of crispness occurred around monolayer moisture content, and the complete loss of crispness occurred at about 9% moisture with the highest hardness.     

Response Surface Methodology Study for Optimization of Effects of Fiber Level, Frying Temperature, and Frying Time on Some Physicochemical, Textural, and Sensory Properties of Wheat Chips Enriched with Apple Fiber

In this study, wheat chips enriched with apple fiber were produced, and response surface methodology was used for the determination of the simultaneous effects of processing variables selected as fiber level (0–15 %), frying temperature (160–180 °C), and frying time (40–60 s) on some physicochemical, textural, and sensorial properties of chips. Ridge analysis was conducted to determine the optimum levels of processing variables. Predictive regression equations with high coefficient of determination (R ²?≥?0.728) were constructed. Addition of apple fiber increased the dry matter; ash content; L, a, and b values of samples, while increase of frying temperature caused decrease of the hardness values. Overall acceptability of chips enriched with apple fiber decreased with the increase of frying temperature, but wheat chips enriched with apple fiber and fried at low temperatures received highest sensory score. Ridge analysis showed that maximum taste score would be attained at fiber level?=?15 %, frying temperature?=?170 °C and frying time?=?40 s.     

Mechanical and physical properties of thermally modified Scots pine wood in high pressure reactor under saturated steam at 120, 150 and 180 °C

Scots pine sapwood and heartwood were thermally modified under saturated steam at 120, 150 and 180 °C in a high pressure reactor. Mechanical properties such as dynamic and static modulus of elasticity (MOE), static modulus of rupture (MOR), Brinell hardness and impact toughness were evaluated. The static MOE for sapwood did not decrease substantially (approximately 1 %), not even with a high mass loss of more than 12 %, when the wood was modified at 180 °C. Static MOE of the wood increased approximately 14 %, when modified at 150 °C. Surprisingly, MOR increased by 15 %, when modified at 150 °C with mass loss of 2.3 %. Whereas impact strength and hardness decreased somewhat, when modified at 180 °C. Moreover, high anti-swelling efficiency values were obtained (60 % for sapwood and 52 % for heartwood) when modified at 180 °C.     

Effect of Steam-Assisted Hybrid Cooking on Textural Quality Characteristics,Cooking Loss,and Free Moisture Content of Beef

Semitendinosus muscles were cooked in a steam-assisted hybrid oven and also convection ovens at three different oven temperatures (180, 210, and 240°C) until three different end point temperatures [65°C (medium-rare), 72°C (medium), 80°C (medium-well)] were reached. Textural properties of cooked beef were investigated by the Warner Bratzler shear test and texture profile analysis. Cooking loss and free moisture content of muscle tissue was determined for each cooking condition. In addition, sensory analysis was carried out in order to compare with the instrumental results and correlations between instrumental texture parameters and sensory results. Steam-assisted hybrid oven cooking of beef resulted in a tougher texture, higher cooking loss, and lower free moisture content than convection cooking. High correlation coefficients (r² > 0.70) were observed between instrumental texture measurements and sensory results for all ovens, especially in terms of tenderness. The free moisture content and adhesiveness values were also correlated well with juiciness (r² > 0.70) for all oven types.     

Effects of variety and stage of fruit ripeness on the physicochemical and sensory characteristics of deep‐fat‐fried banana chips

The quality of banana chips prepared from two different varieties of banana, Pisang Abu and Pisang Nangka, at the ‘green’ and ‘trace of yellow’ stages of ripeness was studied. The fruits were peeled, sliced to a thickness of 2 mm and deep‐fat fried in refined, bleached and deodorised (RBD) palm olein at 180 ± 5 °C for 3 min. The quality parameters determined for fresh bananas were total soluble solids, pH, acidity, carbohydrate, sugar content, fat, protein, moisture content, ash, fibre, colour and fruit firmness. The results showed that Abu had a higher carbohydrate content than Nangka at both stages of ripeness before frying. No sucrose was detected in Nangka. The quality parameters determined after deep‐fat frying were moisture content, water activity, oil absorption, crispness and sensory evaluation. The moisture content and water activity of Abu chips were lower than those of Nangka chips. The texture of chips prepared from Abu at stage ‘green’ showed more crispness than the other three samples. Sensory evaluation showed that chips prepared from Abu at both stages of ripeness presented better colour, flavour, odour, texture and overall acceptability than those prepared from Nangka. Based on the matrix of correlation coefficients, fresh bananas with higher fruit firmness and carbohydrate content gave banana chips with higher crispness and oil absorption. © 2001 Society of Chemical Industry     

Effect of Osmotic Dehydration and Pectin Edible Coatings on Quality and Shelf Life of Fresh-Cut Melon

The aim of this work was to investigate the influence of osmotic dehydration and pectin edible coating on quality parameters of fresh-cut melon. Fruits were osmodehydrated in 40°Bx sucrose solution containing 0.5% calcium lactate or dipped in 0.5% calcium lactate solutions. Then, samples were coated with 1% pectin. Melon pieces dipped in sanitizing solution (nontreated sample) were used as control. Weight loss, respiration rate, firmness, color parameters (lightness, chroma, and whiteness index), sensory acceptance, microbial growth, and structural changes of fruits were evaluated during storage at 5 °C for 14 days. The shelf life of the control sample was limited to 9 days due to microbial growth and sensory rejection, while treated samples showed a shelf life of 14 days. Higher preservation of firmness in coated samples was attributed to the action of calcium salt on melon structure, causing a strengthening of the cell wall. Calcium lactate also inhibited microbial growth along storage, improving microbiological stability of fresh-cut melon. The use of calcium lactate dips and pectin edible coatings hindered weight loss and maintained fruit color characteristics during the storage time. However, these pretreatments probably masked melon taste, reducing the sensory acceptance scores at the end of shelf life study. The combination of osmotic dehydration and pectin coatings was a good preservation alternative for fresh-cut melon, since it improved fruit sensory acceptance, promoting the reduction of product respiration rate, as well as the maintenance of quality parameters during 14 days.     

Correlation Between Electrical Conductivity of the Gutted Fish Body and the Quality of Bighead Carp (Aristichthys nobilis) Heads Stored at 0 and 3 °C

The changes in impedance change ratio (Q value), pH value, texture, K value, total volatile basic nitrogen (TVB-N), total aerobic count (TAC), drip loss, and sensory assessment (SA) of bighead carp (Aristichthys nobilis) during 0 and 3 °C storage were investigated. Simultaneously, correlation models were developed by analyzing the correlation between the measured values. The results indicate that during postmortem storage, Q value is significantly (p?<?0.05) related to pH value and texture indexes (hardness, adhesiveness, springiness, cohesiveness, and resilience); during long-term storage, SA exceeds the acceptable limit on the 15th day at 0 °C and the 12th day at 3 °C, while K value, TVB-N, TAC, and drip loss increase to 72.4 %, 18.9 mg/100 g, 4.82 log₁₀ cfu/g, and 7.09 % at 0 °C, and 78.5 %, 14.0 mg/100 g, 4.97 log₁₀ cfu/g, and 5.08 % at 3 °C, respectively. Meanwhile, Q value declines to 18.9 % at 0 °C and 12.7 % at 3 °C. The correlation coefficients between Q and K values, TVB-N, TAC, drip loss, and SA are 0.955, 0.964, 0.966, 0.965, and 0.994 at 0 °C, and 0.969, 0.967, 0.979, 0.960, and 0.996 at 3 °C, respectively, indicating significant linear relationships (p?<?0.05). Therefore, Q value can be used as a fast nondestructive method to estimate the quality of bighead carp heads during storage at 0 and 3 °C.     

A Comparison Between E-Beam Irradiation and High-Pressure Treatment for Cold-Smoked Salmon Sanitation: Shelf-Life, Colour, Texture and Sensory Characteristics

The effect of electron beam irradiation and high-pressure treatment on the characteristics of cold-smoked salmon during refrigerated storage at 5 °C was investigated. Irradiation at 1–4 kGy and high-pressure treatments at 450 MPa for 5–25 min reduced total viable counts and delayed microbial growth. Irradiation induced a slight decrease in redness (a*), whereas high-pressure treatment resulted in a brighter (L*) appearance of smoked salmon. Higher values of hardness and shear strength were recorded for pressurized samples. Total biogenic amine concentration in smoked salmon held for 20 days at 5 °C was lowered by 81 % in samples irradiated at 2 kGy, and by 46 % in samples pressurized at 450 MPa for 25 min. Smoked salmon irradiated at 1 or 2 kGy had negligible sensory (appearance, odour and flavour) alterations, but lower sensory preferences in the rank order test were observed for 3 and 4 kGy samples. Pressurization for 5 min at 450 MPa induced moderate sensory changes, which were more marked after 15 or 25 min at 450 MPa. These results point to the usefulness of E-beam radiation at 1.5 kGy to assure a safe product of sensory characteristics similar to those of untreated smoked salmon.     

The effects of low mixing temperature on dough rheology and bread properties

In this research, the effects of a low mixing temperature on dough rheology and the quality of bread were investigated. In the experiments, strong flour samples (Type 550), 1.5% salt, 3% of yeast and 1% additive mixture were used and dough samples were mixed at 17 °C (low temperature), 23 °C (control) and 30 °C (high temperature). Five different periods (0, 30, 60, 90 and 120 min) were applied at the bulk fermentation stage. At the final proofing stage, the dough was fermented until it reached a constant height. It was determined that almost every bread from dough samples mixed at 17 °C resulted in not only the highest bread volume and bread weight, but also the best texture, elasticity and crumb structure. The results of dough samples mixed at 23 °C were worse than those of dough samples mixed at 17 °C. The worst results were obtained from dough samples mixed at 30 °C (high temperature). As a result, it may be concluded that the quality of bread from dough samples mixed at low temperature (17 °C) is superior to those from dough samples mixed at the higher temperatures. Besides these findings, it may also be stated that prolonging the period of bulk fermentation in dough samples mixed at 17 °C positively develops baking performances.     

Effects of Modified Atmosphere Packaging on the Physicochemical Characteristics of Ciku ( Achras sapotaL) at Various Storage Temperatures

The physicochemical changes in ciku during storage at various temperatures and the effect of various techniques of modified atmosphere packaging (MAP) at 5, 10, 15°C and ambient were examined by monitoring fruit texture, weight loss, soluble solids content, pH, sucrose, fructose, glucose, pectin, tannin, ascorbic acid and microbial infection. Under MAP, ciku could be stored for 4 weeks at 10°C and 3 weeks at 15°C, while without MAP the storage life was shorter by 1 week. Packaging in low-density polyethylene film (LDPE) was highly effective in maintaining the texture and weight of cold-stored fruits. Fruits stored at 5°C experienced chilling injury, observed as their inability to ripen properly, even after 3 days at room temperature in the presence of 50 g kg⁻¹ calcium carbide. The ascorbic acid content was highest in vacuum-packed fruits followed by the other LDPE packagings. LDPE packaged fruits also received the highest sensory scores for taste, colour, texture and overall acceptability in cold-stored ciku. The unsealed nature and heating involved in shrink wrapping did not favourably affect the storage life of ciku. MAP alleviated the chilling injury which occurred in ciku stored at 10°C but not at 5°C.     

Quality Attributes of Fruit Bar Made from Papaya and Tomato by Incorporating Hydrocolloids

Fruit bar was prepared from blend of ripe papaya and tomato pulps (variety, Red Lady and C.V. Naveen, respectively) in the ratio 75:25 on weight basis. Effects of hydrocolloids viz. pectin (P), starch (S), and ethyl cellulose (EC) and its three different levels on physico-chemical, sensory, and textural characteristics were investigated. It was found that seven different samples of fruit bar had moisture contents of 20.9–22.1% and total soluble solids 78.1–78.8°Brix while pH, browning index, and vitamin C contents were in the following ranges, 4.3–4.50, 0.137–0.150 (OD), and 40.5–41.4 mg/100 g respectively. Texture study revealed that hydrocolloids incorporation at 1% each of starch + ethyl cellulose and pectin + starch, 1.5% each caused significant (P < 0.05) increased in compactness/hardness of texture. Sensory characteristics study revealed that all the samples of fruit bar were acceptable in taste, color, and aroma but differed significantly (P < 0.05) in their texture. The samples packed in LDPE bags (100 μ), stored at 35–45°C for four months. It was found that there were significant (P < 0.05) changes in physico-chemical properties like acidity and vitamin C during four months storage. No significant (P < 0.05) effect on either browning index (OD) or deterioration in color, taste, and aroma of these samples was observed. During four months storage change in color and texture were not uniform for all treatments. Addition of 0.5 and 1% of each starch + ethyl cellulose were effective in maintaining the color while 0.5, 1, and 1.5% of each P + S was effective in improving the texture during four months storage.     

Effect of drying methods on osmotically dehydrated cashew apples

Matured ripe cashew apples were transversely cut into 10 mm, 15 mm and 20 mm slices and immersed in sugar solutions of 52°Brix, 60°Brix and 68°Brix, for 10 h. The osmotic temperature was maintained at 27 °C in a water bath. Osmosed samples were subsequently dried in either an air-oven (50 °C) or a vacuum-drier (50 °C), both for 6 h.The instantaneous moisture content (d.b) of osmosed cashew apples decreased with increasing immersion time and osmotic solution concentration, but also increased with increasing slice thickness. The water loss, solids gain and percentage weight reduction increased with increasing osmotic solution concentration and immersion time, but decreased with increasing slice thickness. Osmotically dried samples received high acceptability. Sample pre-osmosed in 60°Brix and 68°Brix solutions were significantly better (P>0.05) than those pre-osmosed in a 51°Brix solution. A significant difference (P>0.05) between the osmo-oven and osmo-vacuum dried cashew apples could not be ascertained (under the conditions of the investigation).     

Microencapsulation of Andes Berry (Rubus glaucus Benth.) Aqueous Extract by Spray Drying

The Andes berry (Rubus glaucus Benth.), a tropical fruit with a high anthocyanin content and pleasant aroma, was selected for spray drying to produce solids that preserve the sensory characteristics (colour, odour and taste) of the fresh fruit. A factorial design (9?×?2) was implemented to evaluate the influence of the encapsulating agent (maltodextrin DE 20, arabic gum, corn starch, yucca starch, Capsul® TA and Hi-Cap^TM 100, as well as three mixtures of them) and the nozzle diameter (1.0 and 2.0 mm) on the characteristics of solids, anthocyanin content, moisture and water activity. All solids showed water activity values (a _w) between 0.199 and 0.422, and particle size ranging from 3 to 15 μm according to microscopy results. The samples exhibiting the highest anthocyanin content were subjected to a discriminative sensory analysis. The Andes berry microencapsulates obtained with Hi-Cap^TM 100 and maltodextrin DE 20 as wall materials were chosen because of their sensory properties. The release of anthocyanins as well as volatile aroma compounds by water dissolution was confirmed by both liquid and gas chromatography coupled to mass spectrometry (HPLC-MS and GCMS, respectively). The chroma (C*ab) and a* values of the solutions were higher than those of the powders, which indicated a more intense red colour. Thermal analyses (thermogravimetric analyses and differential scanning calorimetry) showed that these two solids were stable up to 100 °C under a nitrogen atmosphere. Remarkably, the anthocyanin content did not change during 180 days at 18 °C and a relative humidity of less than 60 %. However, the shelf life of these products is highly dependent on the humidity during storage because a relative humidity increase causes significant damage to the microcapsule structures and the loss of the encapsulated materials.