Comparison of Phenolic and Volatile Compounds in MD2 Pineapple Peel and Core.

The peel and core discarded from the processing of MD2 pineapple have the potential to be valorized. This study evaluated the functional and volatile compounds in the extracts of MD pineapple peel and core (MD2-PPC). The total soluble solids, pH, titratable acidity, sweetness index, and astringency index were 9.34 °Brix, 4.00, 0.74%, 12.84, and 0.08, respectively, for the peel and 12.00 °Brix, 3.96, 0.32%, 37.66, and 0.03, respectively, for the core. The fat and protein contents of the peel and core were found to be significantly different (p < 0.05). The total phenolic (TPC) and flavonoid contents (TFC) were significantly higher in the peel. The peel also showed better antioxidant activity, with a half-maximal inhibitory concentration (IC50) of 0.63 mg/mL for DPPH free radical activity compared with the core. The TPC of different phenolic fractions from peel extract was highest in the glycosylated fraction, followed by the esterified, insoluble-bound, and free phenolic fractions. GC-MS analysis identified 38 compounds in the peel and 23 in the core. The primary volatile compounds were 2-furan carboxaldehyde, 5-(hydroxymethyl), and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The identification of phenolics and volatile compounds provides important insights into the valorization of (MD2-PPC) waste.

Simultaneous kinetics formation of heterocyclic amines and polycyclic aromatic hydrocarbons in phenylalanine model system.

A combination of chemical model system with kinetics study was used to investigate the simultaneous formation of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). Heating a mixture of phenylalanine, creatinine, and glucose at a commonly practiced household cooking time and temperature successfully differentiated the rate formation (k) of HCAs and PAHs. The good fit suggested that the simultaneous formation was an endothermic bimolecular reaction, and followed the first-order model. The rate formation (k) of HCAs and PAHs significantly increased with increasing heating time and temperature. Only 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) showed degradation rate (k) at higher heating temperatures of 210 °C and 240 °C respectively. Increasing phenylalanine concentration increased the possibility of higher HCAs and PAHs formation. The activation energy (Ea) showed that heating phenylalanine mixture resulted in higher rate of formation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and benzo[b]fluoranthen (BbF).

Selection of Vegetable Oils and Frying Cycles Influencing Acrylamide Formation in the Intermittently Fried Beef Nuggets.

This study aims to investigate the effect of different vegetable oils and frying cycles on acrylamide formation during the intermittent frying of beef nuggets. Different vegetable oils, palm olein (PO), red palm olein (RPO), sunflower oil (SFO), and soybean oil (SBO), were used for a total of 80 frying cycles. Oil was collected at every 16th frying cycle and analyzed for peroxide value (PV), p-anisidine value (p-AV), free fatty acid (FFA), total polar compound (TPC), polar compound fractions, and fatty acid composition (FAC). Total oxidation (TOTOX) value was calculated, and acrylamide content was quantified in the nuggets. Regardless of the oil type, PV, p-AV, and TOTOX initially increased but gradually decreased. However, FFA and TPC continued to develop across the 80 frying cycles. The C18:2/C16:0 remained almost unchanged in PO and RPO but dropped progressively in SFO and SBO. The lowest acrylamide content in fried products was observed in the PO, while the highest content was observed in RPO. Bivariate correlation analysis showed no significant (p ≤ 0.05) correlation between oil quality attributes and acrylamide concentration. The oil type but not the frying cycle significantly affected the acrylamide concentration in beef nuggets.

Storage stability and degradation kinetics of bioactive compounds in red palm oil microcapsules produced with solution-enhanced dispersion by supercritical carbon dioxide: A comparison with the spray-drying method.

Solution-enhanced dispersion by supercritical carbon dioxide (SEDS) and spray drying (SD) were used to microencapsulate red palm oil (RPO) to prolong the functionality of carotenes and vitamin E. The protective effects provided by SEDS and SD were evaluated in terms of the oxidative stability (65 °C for 35 days), fatty acid compositions, color change and degradation kinetics of carotenes and vitamin E (25 °C, 45 °C, 65 °C, and 85 °C for up to 198 days). SEDS microcapsules (SEDS-M) were the most oxidatively stable (total oxidation (Totox): 26.5), followed by SD microcapsules (SD-M) (34.9) and RPO (56.7). Degradation of carotenes and vitamin E fitted well a first-order kinetic model (average absolute relative deviation = 2-16%). SEDS-M offered better protection to vitamin E (Ea = 36 kJ/mol), whereas SD-M provided better protection for α +â€¯ß carotene (Ea = 29 kJ/mol). Overall, encapsulation protected RPO during storage, with SEDS-microencapsulated RPO performing better than SD-microencapsulated RPO.

Effect of Different Amino Acids and Heating Conditions on the Formation of 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and Its Kinetics Formation Using Chemical Model System.

The formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was investigated using a kinetic study approach as described by first-order, Arrhenius, and Eyring equations. Chemical model systems with different amino acid precursors (proline, phenylalanine, and glycine) were examined at different times (4, 8, 12, and 16 min) and temperatures (150, 180, 210, 240, and 270 °C). PhIP was detected using high-performance liquid chromatography equipped with fluorescence detector (HPLC-FLD). The good fit in first-order suggested that PhIP formation was influenced by the types of amino acids and PhIP concentration significantly increased with time and temperature (up to 240 °C). PhIP was detected in proline and phenylalanine model systems but not in the glycine model system. The phenylalanine model system demonstrated low activation energy (Ea) of 95.36 kJ/mol that resulted in a high rate of PhIP formation (great amount of PhIP formed). Based on the ∆S‡ values both proline and phenylalanine demonstrated bimolecular rate-limiting steps for PhIP formation. Altogether these kinetic results could provide valuable information in predicting the PhIP formation pathway.

Current trends of tropical fruit waste utilization.

Recent rapid growth of the world's population has increased food demands. This phenomenon poses a great challenge for food manufacturers in maximizing the existing food or plant resources. Nowadays, the recovery of health benefit bioactive compounds from fruit wastes is a research trend not only to help minimize the waste burden, but also to meet the intensive demand from the public for phenolic compounds which are believed to have protective effects against chronic diseases. This review is focused on polyphenolic compounds recovery from tropical fruit wastes and its current trend of utilization. The tropical fruit wastes include in discussion are durian (Durio zibethinus), mangosteen (Garcinia mangostana L.), rambutan (Nephelium lappaceum), mango (Mangifera indica L.), jackfruit (Artocarpus heterophyllus), papaya (Carica papaya), passion fruit (Passiflora edulis), dragon fruit (Hylocereus spp), and pineapple (Ananas comosus). Highlights of bioactive compounds in different parts of a tropical fruit are targeted primarily for food industries as pragmatic references to create novel innovative health enhancement food products. This information is intended to inspire further research ideas in areas that are still under-explored and for food processing manufacturers who would like to minimize wastes as the norm of present day industry (design) objective.

Effect of roasting conditions on the browning intensity and structural changes in jackfruit (Artocarpus hetrophyllus) seeds.

Central composite rotatable design (CCRD) was used to optimize the settings for the roasting conditions of jackfruit (Artocapus hetrophyllus) seed (JFS). The response variables studied were; color attributes L*, a*, and b*, browning intensity, and fracturability. The colors L*, a*, b* and browning intensity were well predicted by a second-order polynomial model. Fracturability was predicted by a first-order polynomial. The determination coefficients for colors L*, a*, b*, browning intensity, and fracturability were 0.81, 0.96, 0.93, 0.92, and 0.74 respectively. The fitted models were checked for adequacy using analysis of variance (ANOVA). The optimum roasting conditions were established at a temperature of 153.36 °C, 34.36 min, and pH of 6.34 with composite desirability value of 0.95. Micro-structural studies of both raw and roasted JFS at different roasting levels (i.e., low, medium, and high) were also investigated using scanning electron microscope (SEM). JFS starch granules fell in the B-type category with semi-oval to bell-shaped granules (5-9 µm in diameter). In addition, Fourier Transform Infrared analysis was carried out on both raw and roasted JFS. The IR spectra was in the 4000-1000 cm(-1) region which is described by five main modes; O-H, C-H, C = O, (C-H) CH3, and C-O.

Physicochemical properties of Malaysian-grown tropical almond nuts (Terminalia catappa).

The seeds of Terminalia catappa from Malaysia were analyzed for their physicochemical properties. The following values were obtained: moisture 6.23 ± 0.09 %, ash 3.78 ± 0.04 %, lipid 54.68 ± 0.14 %, protein 17.66 ± 0.13 %, total dietary fibre 9.97 ± 0.08 %, carbohydrate 7.68 ± 0.06 %, reducing sugar 1.36 ± 0.16 %, starch 1.22 ± 0.15 %, caloric value 593.48 ± 0.24 %. Studies were also conducted on amino acid profile and free fatty acid composition of the seed oil. Results revealed that glutamic acid was the major essential amino acid while methionine and lysine were the limiting amino acids. The major saturated fatty acid was palmitic acid, while the main unsaturated fatty acid was oleic acid followed by linoleic acid. In addition, the seed was rich in sucrose and had trace amount of glucose and fructose. Briefly, the seed was high in proteins and lipids which are beneficial to human.

Effect of roasting conditions on color development and Fourier transform infrared spectroscopy (FTIR-ATR) analysis of Malaysian-grown tropical almond nuts (Terminalia catappa L.).

BACKGROUND: Proper roasting is crucial to flavor, color, and texture development in the final product. In recent years, several research studies have been carried out to establish the best optimum roasting conditions for some common edible nuts such as; hazelnut, peanut, and pistachio nut. Although roasting is an important process for nuts and oilseeds, there is little or no information on the development of color, aroma, and textural changes in Terminalia catappa nuts during roasting. RESULTS: Results showed that color formation and browning index were significantly (P < 0.05) influenced by the roasting temperature and time of roasting. However, the fracturability of nuts was significantly (P < 0.05) affected by both temperature of roasting and time as well as pH. The optimized results showed that the best response was reached when the roasting time was 29.9 min, roasting temperature 174.5°C, and pH 6.08, respectively. Moreover, the 3400-1560 cm(-1) carbonyl region for carboxylic acid, alkenes, esters, and amines was found to provide a flavor-print of the roasted tropical almond nut. While, increase in temperature did not produce new carbonyl compounds, it however led to higher concentration of compounds. Scanning electron microscopy of the almond nuts showed that the starch granules were embedded in tissues. CONCLUSION: These results showed that roasting temperature and time of roasting were the main variables that significantly affected the physicochemical properties of roasted tropical almond nuts. Moreover the flavor-prints for the roasted nut were produced in the 3400-1560 cm(-1) carbonyl region. Graphical AbstractEffect of roasting conditions on fracturability and structural morphology of tropical almond nuts (T. catappa).