Analytical approaches for discriminating native lard from other animal fats

Establishing the distinguishable characteristics of lard from other common animal fats might be helpful for authentication initiatives in foods and feeds. In this study, fatty acid and triacylglycerol compositions, thermal and spectroscopic characteristics of native lard (NL), respectively, were compared with those of beef tallow (BT), mutton tallow (MT), and chicken fat (CF) by using gas liquid chromatography (GLC), high-performance liquid chromatography (HPLC), and differential scanning calorimetry (DSC). GLC analysis showed that the comparison of the overall fatty acid data might not be suitable for the discrimination of different animal fats, but the use of the principal component analysis and the percent palmitic acid enrichment factor [PAEF (%)] calculations were useful. HPLC analysis showed that NL displayed a TAG profile, which was quite different from those of either BT or MT, but appeared to be closely similar to that of CF. Results of DSC thermal analysis showed that both melting and crystallization curves of NL were remarkably different from those of other animal fats

Chemical composition and thermal behaviour of tropical fat fractions from solvent-assisted process: a review

Fractional crystallization is a process applied to plant and animal fats to obtain fat products with new functional properties and nutritional values. Fractionation is generally performed through either a dry or a solvent-assisted process. As solvents can wash off the liquid molecules able to entrap the solid component inside, the solvent-crystallization seems to be more efficient than other fractionation procedures. In recent times, fractional crystallization has been investigated for avocado (Persea Americana) butter, engkabang (Shorea macrophylla) fat, palm oil-moringa oil blend, and mee fat (Madhuca longifolia) to prepare solid (stearin) and liquid (olein) fractions. This review sums up the main and recent published studies on chemical and thermal (upon differential scanning calorimetry) properties of fat fractions obtained using solvent-assisted process. It has been argued that the ease of a fat fractionation mainly depends on the thermal characteristics of its triacylglycerol molecules. Fats with low-and high-melting thermal transitions in wide separation would yield fat components with remarkable changes in physico-chemical characteristics, fatty acid and triacylglycerol compositions as well as thermal profiles. The activities involving the use of fat components, during food formulation, may significantly benefit from a further learning of the fats behavior

Effect of Addition of Green Coffee Parchment on Structural, Qualitative and Chemical Properties of Gluten-Free Bread

Green coffee parchment (GCP) is becoming interesting, due to the diffusion of wet processing in which coffee parchment is collected separately; it is one of the less studied coffee by-products, but it is reported to be rich in phenolic compounds and dietary fiber. The addition of GCP (355–500 μm) at 2 % to gluten-free breads was investigated in terms of physical properties (volume, moisture content, water activity, crumb grain, texture, and color), total antioxidant capacity (TAC) and total phenol content during three days of storage. Moreover, the effects of GCP on sensorial characteristics, 5-hydroxymethylfurfural (HMF), and oxidative stability was evaluated. From the sensorial analysis, bread with 2% addition resulted in being acceptable for consumers with no significant differences from the control, while 4% of GCP was discarded by consumers, as it resulted in being too bitter. Moreover, GCP at 2% addition did not modify volume, moisture content, and water activity. On the contrary, GCP deeply affected the color with a darker aspect that was appreciated by consumers. Regarding texture, 2% of GCP did not affect hardness, cohesiveness, and staling process during storage. Interestingly, 2% of GCP significantly improved the TAC and oxidative stability of the bread; in accordance with these results, 2% of GCP reduced the HMF content, thanks to its antioxidant compounds

Sensory properties of iodine-biofortified potatoes

The present study assessed the sensory impact of potatoes biofortification with iodine and the stability of iodine during six months of storage. Four biofortified cultivars (Cupido, Marabel, Orchestra and Universa) and their controls (non-biofortified) were evaluated. Descriptive analysis was applied with a panel to describe the sensory properties, and triangle tests were applied with consumers to evaluate perceivable differences between controls and respective biofortified samples at the end of shelf life. Iodine content was quantified on raw potatoes for three periods of storage. Descriptive analysis showed some differences between controls and iodine-biofortified samples, especially in texture (hardness). However, consumers did not significantly discriminate fortified from unfortified samples. Iodine was stable during storage in all varieties. Orchestra cultivar showed the highest iodine content, while Universa the lowest

Effects of high hydrostatic pressure on physico-chemical and structural properties of two pumpkin species

The effects of high pressure treatments (200, 400, 600MPa for 5 min) and a thermal treatment (85°C for 5 min) were evaluated on cubes of two pumpkin species (Cucurbita maxima L. var. Delica and Cucurbita moschata Duchesne var. Butternut) up to 2 months of refrigerated storage. Increasing the pressure, small parenchyma cells from the pumpkin tissue exhibited collapses and separations, especially for Butternut. This species showed a lower hardness than Delica at time 0. For both species, 400MPa and thermal treatment were the most effective in the inactivation of pectinmethylesterase, which reactivated after 2 months, especially for Butternut. Colorimetric parameters decreased after all treatments. Antioxidant activity resulted affected by pressure, showing a significant increase during storage especially for the samples treated at 200MPa after 2 months, comparable to the thermal treated ones. Among the tested treatments, 400MPa may be considered as the best option for the quality retention during storage

Physical and Thermal Evaluation of Olive Oils from Minor Italian Cultivars

Authentication of extra virgin olive oils is a key strategy for their valorization and a way to preserve olive biodiversity. Physical and thermal analysis have been proposed in this study as fast and green techniques to reach this goal. Thirteen extra virgin olive oils (EVOOs) obtained from minor olive cultivars, harvested at three different ripening stages, in four Italian regions (Abruzzo, Apulia, Sardinia, and Calabria) have been studied. Thermal properties, viscosity and color, as influenced by fatty acid composition and chlorophyll content, have been investigated. The thermal curves of EVOOs, obtained by differential scanning calorimetry, were mostly influenced by the oleic acid content: a direct correlation with the cooling and heating enthalpy and an indirect correlation with the cooling transition range were observed. The minor fatty acids, and particularly arachidic acid, showed an influence, mostly on the heating thermograms. Viscosity and color showed respectively a correlation with fatty acids composition and chlorophyll content, however they didn’t result able to discriminate between the samples. Thanks to the principal component analysis, the most influencing thermal parameters and fatty acids were used to cluster the samples, based on their botanical and geographical origin, resulting instead the harvesting time a less influential variable

Inulin-based emulsion filled gel as fat replacer in shortbread cookies: Effects during storage

Shortbread cookies with 0, 20, 40 and 50% fat replacement were obtained using an emulsion filled gel (EFG) based on inulin and extra virgin olive oil and studied during 60 storage days. Increasing the amount of EFG in shortbread cookies, higher volumes and harder texture were observed, in relation to the higher water availability and the lower fat content. Thermal analysis conducted by means of DSC and 1H-NMR confirmed the key role of lipids and water status on the mechanical properties of shortbread cookies. Darker colour and toasted notes were registered for increasing levels of EFG, in relation to the presence of inulin involved in the Maillard reaction. During storage, all the cookies resulted very stable regarding dimensions, colour and rancidity perception; only slight texture changes were observed, probably related to the moisture redistribution among the cookies components. EFG can be proposed as valuable ingredient to replace fats in shortbread cookies, allowing the use of the health claim “reduced saturated fat content” already from 40% butter substitution

Effect of different atmospheric and subatmospheric cooking techniques on qualitative properties and microstructure of artichoke heads

Quartered Violetto artichokes were cooked with different treatments (boiling, steaming, sous vide and vacuum cooking) at the same cooking value at the thermal centre. Then, the physical (moisture content, texture and colour), histological and chemical (phenolic, 5-hydroxymethylfurfural (HMF) and furan content, total antioxidant capacity) features of bracts and hearts were assessed. A deeply modified microstructure was observed in boiled and steamed samples with an evident decrease in hardness both for bracts and hearts. Lightness of two anatomical parts was decreased by all the treatments (with the exception of sous vide bracts). The highest total colour difference was recorded for steamed samples, whereas the lowest was noted for sous vide samples. Steamed and sous vide artichoke exhibited the highest total phenolic content and total antioxidant capacity. Sous vide samples exhibited the highest concentrations of HMF, 2-furan-methanol and 2,4-dihydroxy-2,5-dimetyl-3(2H)-furanone, whereas the by-product 5-metylfuraldheide was only detected in the steamed product

High pressure and thermal processing on the quality of zucchini slices

AbstractIn response to the market demand for low processed vegetables, high-pressure treatments (400,600 MPa; 1,5 min) were applied on zucchini slices and compared to a traditional blanching treatment. Histological observations, texture and color analysis, pectinmethylesterase (PME) and antioxidant (DPPH) activities were measured and compared to untreated samples. The histological observations revealed that the longer high-pressure treatments (5 min) led to more extended cell lysis and dehydration than the shorter ones (1 min) and blanching. High-pressure treatments resulted less effective than blanching on PME inactivation, with the best results obtained at 400 MPa for 1 min. Comparable texture parameters were observed for high-pressured and blanched samples. The negative correlation found between PME activity and the texture parameter 'distance of the first peak force' revealed an effect of PME on the texture recovery after treatments. High pressure led to a general browning of zucchini parenchyma and to DPPH drop. The correlations found between DPPH and color suggest the common nature of the phenomena. The influence of pressure and time on the studied parameters was revealed by two-way ANOVA. Principal component analysis clustered together the four high-pressure-treated samples, being clearly divided by blanched and untreated ones