Paweł Górnaś

Acute anti-hyperglycaemic effects of an unripe apple preparation containing phlorizin in healthy volunteers: a preliminary study.

BACKGROUND The health-promoting properties of apples are directly related to the biologically active compounds that they contain, such as polyphenols. The objective of this study was to prepare a low-sugar, fibre- and phlorizin-enriched powder from unripe apples and to gain insight regarding its anti-hyperglycaemic activity in healthy volunteers. RESULTS The unripe apples (Malus domestica Borkh.) were collected 30 days after the full bloom day; blanched and pressed to obtain apple pomace which was then processed with a food cutter, oven-dried and milled to prepare apple powder. The concentrations of total sugars, water-soluble pectin and phlorizin in the apple preparation were 153.44 ± 2.46, 27.73 ± 0.51 and 12.61 ± 0.15 g kg(-1), respectively. Acute ingestion of the apple preparation improved glucose metabolism in the oral glucose tolerance test (OGTT) in six healthy volunteers by reducing the postprandial glucose response at 15 to 30 min by approximately two-fold (P < 0.05) and by increasing urinary glucose excretion during the 2- to 4-h interval of the OGTT by five-fold (P < 0.05). CONCLUSION The results obtained indicate that the dried and powdered pomace of unripe apples can be used as a health-promoting natural product for the reduction of postprandial glycaemia and to improve the health of patients with diabetes.

Tocochromanols composition in kernels recovered from different apricot varieties: RP-HPLC/FLD and RP-UPLC-ESI/MSn study

Composition of tocochromanols in kernels recovered from 16 different apricot varieties (Prunus armeniaca L.) was studied. Three tocopherol (T) homologues, namely α, γ and δ, were quantified in all tested samples by an RP-HPLC/FLD method. The γ-T was the main tocopherol homologue identified in apricot kernels and constituted approximately 93% of total detected tocopherols. The RP-UPLC-ESI/MSn method detected trace amounts of two tocotrienol homologues α and γ in the apricot kernels. The concentration of individual tocopherol homologues in kernels of different apricots varieties, expressed in mg/100 g dwb, was in the following range: 1.38–4.41 (α-T), 42.48–73.27 (γ-T) and 0.77–2.09 (δ-T). Moreover, the ratio between individual tocopherol homologues α:γ:δ was nearly constant in all varieties and amounted to approximately 2:39:1.

Sesamin and sesamolin as unexpected contaminants in various cold-pressed plant oils: NP-HPLC/FLD/DAD and RP-UPLC-ESI/MS(n) study.

Thirteen cold-pressed oils (Japanese quince seed, black caraway, flaxseed, rapeseed, hemp, peanut, sunflower, pumpkin, hazelnut, poppy, walnut, almond and sesame oil) manufactured by the same company over a 2-year period (2011–12) were assessed for lipophilic compounds. The presence of sesamin and sesamolin, two characteristic lignans of sesame oil, were detected in all tested plant oils. Both lignans were identified by NP-HPLC/FLD/DAD and confirmed by a RP-UPLC-ESI/MSn method. The lowest amount of sesamin and sesamolin was found for Japanese quince seed oil (0.10 and 0.27 mg/100 g), and the highest, excluding sesame oil, for almond oil (36.21 and 105.42 mg/100 g, respectively). The highly significant correlation between sesamolin and sesamin concentrations was found in all samples tested (r = 0.9999; p < 0.00001). These results indicate contamination of cold-pressed oils from the same source. This investigation highlights the fact that increasing the range of products manufactured by the same company can contribute to a lesser regard for the quality of the final product. Moreover, less attention paid to the quality of final product can be related to the health risks of consumers especially sensitive to allergens. Therefore, proper cleaning of processing equipment is needed to prevent cross-contact of cold-pressed oils.

The effects of muffins enriched with sour cherry pomace on acceptability, glycemic response, satiety and energy intake: a randomized crossover trial

BACKGROUND Sour cherry pomace (CP), a by-product obtained during fruit processing, was used to replace wheat flour in a muffin formula. The influence of the most sensory acceptable muffins on glycemic response, appetite sensation, and energy intake during subsequent meal in a randomized crossover trial was studied. RESULTS It is acceptable to incorporate up to 30% CP into muffin formulas. With CP-treated muffins glucose responses were significantly lower at 30, 45, and 60 min intervals, and the incremental peak glucose was 0.40 and 0.60 mmol L(-1) lower than for plain muffins (PM). The CP-enriched muffins showed an incremental area under the blood glucose response curve values lower than that of PM. 20% CP and 30% CP resulted in improved satiety and induced a lower energy intake at a test meal ingested 3 h later (-13.7%; -15.1%) as compared to PM, respectively. CONCLUSION CP may be a good functional ingredient for bakery products that assists in managing glucose levels, satiety, and subsequent energy intake in healthy individuals.

Impact of Species and Variety on Concentrations of Minor Lipophilic Bioactive Compounds in Oils Recovered from Plum Kernels

The profile of bioactive compounds (carotenoids, tocopherols, tocotrienols, phytosterols, and squalene) in oils recovered from the kernels of 28 plum varieties of hexaploid species Prunus domestica L. and diploid plums Prunus cerasifera Ehrh. and their crossbreeds were studied. Oil yields in plum kernels of both P. cerasifera and P. domestica was in wide ranges of 22.6-53.1 and 24.2-46.9% (w/w) dw, respectively. The contents of total tocochromanols, carotenoids, phytosterols, and squalene was significantly affected by the variety and ranged between 70.7 and 208.7 mg/100 g of oil, between 0.41 and 3.07 mg/100 g of oil, between 297.2 and 1569.6 mg/100 g of oil, and between 25.7 and 80.4 mg/100 g of oil, respectively. Regardless of the cultivar, β-sitosterol and γ-tocopherol were the main minor lipophilic compounds in plum kernel oils and constituted between 208.5 and 1258.7 mg/100 g of oil and between 60.5 and 182.0 mg/100 g of oil, respectively. Between the studied plum species, significant differences were recorded for δ-tocopherol (p = 0.007), 24-methylenecycloartanol (p = 0.038), and citrostadienol (p = 0.003), but they were insufficient for discrimination by PCA.

Lipophilic bioactive compounds in the oils recovered from cereal by‐products

BACKGROUND The by-products of seven different cereal grains were investigated as a source of extractable oil, rich in lipophilic bioactive compounds. RESULTS Oil yields (g kg(-1) DW) recovered from cereal by-products were as follows: 189 (rice bran) > 112 (wheat germ) > 74 (corn bran) > 58 (oat bran) > 41 (buckwheat bran) > 39 (spelt bran) > 33 (wheat bran) > 27 (rye bran). The main fatty acids identified in the studied oil samples were palmitic acid (11.39-17.23%), oleic acid (11.76-42.73%), linoleic acid (35.54-62.65%) and α-linolenic acid (1.05-9.46%). The range of total tocochromanols and phytosterols in the obtained oils was 0.369-3.763 and 1.19-35.24 g kg(-1) of oil, respectively. The oils recovered from buckwheat and corn bran, and wheat germ were dominated by tocopherols (99.9, 84.2 and 96.5%, respectively), whereas the oat, rice, rye, spelt, wheat bran oils were rich in tocotrienols (73.9, 79.6, 78.1, 90.6 and 73.8%, respectively). The campesterol and β-sitosterol constituted 10.1-32.5 and 30.4-63.7%, respectively, of total phytosterols contents identified in all of the studied samples. CONCLUSION The present study demonstrated that oils recovered from the cereal by-products are richer sources of bioactive compounds, compared with traditional oils.

Sea buckthorn (Hippophae rhamnoides L.) vegetative parts as an unconventional source of lipophilic antioxidants

The profile of lipophilic antioxidants in different vegetative parts (leaves, shoots, buds and berries) was studied in sea buckthorn (Hippophae rhamnoides L.) male and female plants collected in the end of spring. Five lipophilic compounds, i.e. three tocopherol homologues (α, β and γ), plastochromanol-8 and β-carotene, were identified in each vegetative part of male and female sea buckthorn plants at the following concentrations: 7.25–35.41, 0.21–2.43, 0.41–1.51, 0.19–1.79 and 4.43–24.57 mg/100 g dry weight basis. Additionally, significant amounts of α-tocotrienol (1.99 mg/100 g dry weight basis) were detected in buds. The α-tocopherol and β-carotene were predominant lipophilic antioxidants in each vegetative part, accounting for 78.3–97.0% of identified compounds. The greatest amounts of lipophilic antioxidants were found in leaves, especially of female plants. Nevertheless, apart from leaves, also shoots of plants of both sexes seem to be a good source of α-tocopherol and β-carotene.

Varied Composition of Tocochromanols in Different Types of Bran: Rye, Wheat, Oat, Spelt, Buckwheat, Corn, and Rice

The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.

Bioaccessibility of defatted lupin seed phenolic compounds in a standardized static in vitro digestion system

Phenolic compounds are secondary plant metabolites whose beneficial health effects make them of intense interest to researchers. The aim of the study presented here was to evaluate the change in the phenolic compound profile of lupin seed in in vitro digestion. The most abundant phenolic compounds in undigested lupin seeds were mostly apigenin derivatives. The in vitro digestion of lupin seeds resulted in qualitatively altered phenolic compound profiles. Approximately 80% of phenolic compounds were released from lupin seeds during the in vitro digestion, which simulated gastric processes. Continued digestion, imitating the intestinal phase, additionally increased the bioaccessibility of lupin seed polyphenols by about 10%. The in vitro gastrointestinal model was also used to elucidate how the content of native phenolic compounds affects the digestion susceptibility of lupin seed proteins. An inverse correlation between protein digestibility and phenolic compound content, was also demonstrated.